今年八月，當胡錦濤拿起電話，與一位正在重慶視察的高級反腐官員交談的時，特殊的儀器檢測到他正遭到監聽——監聽器的那頭是這座西南中心城市的當地官員。

在這場遠未收場的政治大地震中，這個發現連同其他的監聽行為所招致的官方調查，在重慶的魅力型領導薄熙來的倒臺中狠狠地推了一把。

直到現在，薄熙來的倒臺大致被塑造成了這樣一個故事：一個民粹主義者把自己追逐北京最高領導地位的進程編排得過於激進，終因其妻被控因商業糾紛謀殺了英國商人尼爾·伍德而被斬落馬下。然而，這此前僅在黨的核心中有所暗示的隱秘監聽也為這醜事記上了一筆，它似乎又提供了一個魅力無窮的理由，誘使著黨的領導們向薄熙來開刀。

中國主席被監視的故事同樣顯示了，在這個一黨專政的國家中，領導人間的相互不信任到達了何種程度。爲了保持對整個社會的控制，領導人們早已向高端監控技術敞開了懷抱。不過有些領導則把這套也用在了同僚身上——這與共產黨統治初期的那些花樣如出一轍。

“這是一個滋長著不信任與暴力的社會，”研究中共精英階層半世紀以來的陰謀的歷史學家Roderick MacFarquhar說，“領導人們知道自己必須背上長眼，因為你永遠不知道誰會在後面捅上一刀。”

近乎一打與共產黨有所關聯的人證實了關於竊聽的消息，他們都懼于處分而選擇了匿名，他們同樣證實了一個遍佈重慶的竊聽器安裝計劃。但在黨關於薄熙來倒臺的官方版本里，這一點被省略了。

官方的陳述和眾多的外國關注都聚焦于最易於理解的11月尼爾·伍德之死上。當薄熙來的公安局長王立軍被去職，并因害怕被捲入薄家的問題而逃往成都美國大使館時，他在大使館里說的也主要是關於尼爾·伍德之死的問題。

對這起命案的敘述構成了醜聞的軸心，它為薄熙來的對手們提供了無懈可擊的清除他的理由。但黨的內部人員透露，這次監聽被視為對中央當局的直接挑戰。它向他們展示了，現正受到嚴重違紀調查的薄熙來，爲了能在中國攫取更大的權力，他作好了做得多絕的準備。今秋黨的高級領導班子將重新洗牌，它的頂層空缺也將因而釋出，然而由薄熙來擔當一席早被懷疑是不堪信任的，此次的竊聽更加劇這一疑竇。

“全中國每個人都在改進他們的維穩系統，”一位中央政府的媒體口徑官員在提及監控手段的時候說，“但不是每個人都敢監視黨的中央領導人的。”

據包括編輯、學者和與軍方有聯繫的人士在內的資深共產黨員所說，薄熙來的竊聽行為在多年以前有開始了，當時是作為國家金融系統監控的組成部份，表面上是爲了打擊犯罪和維護地方政治穩定。

其中一名他們延攬的知名網絡安全專家是北京郵電大學的校長方濱興，他被稱為中國的巨型網絡控制系統“長城防火牆”之父。最近，據國有新聞媒體報導，方濱興建議重慶在新的警務信息中心中使用云基礎的計算機技術。去年底，王立軍被聘為方濱興的大學的兼職教授。

薄熙來和王立軍共同發動了對他們稱為“掌握了重慶經濟生活的巨大份額的犯罪團夥”的攻擊。在採訪中，這次清剿的對象們驚異于當地警方攔截他們的溝通信息的規模和果決。

“在電話里，我們不敢提到薄熙來或者王立軍，”如今流亡海外躲躲藏藏的開發商李軍說。權宜之計是，李軍說，他和他的商人夥伴們通過塗污字條、拆掉手機電池和囤積未經註冊的SIM卡，以在清剿上馬時阻礙監控。

李莊是來自北京一所人脈強大的法律事務所的律師，他回憶起一位當事人的表兄弟們曾送給他一堆沒註冊的SIM卡，并讓他警惕當地的監聽。儘管有了種種小心，重慶警方最終還是在北京郊區逮捕了李莊。他曾在900英里外的地方打過電話給一位他的當事人的妻子，約定當天晚些時候要在醫院見她一面。

“他們早就在那裡埋伏好了，”李莊說。他還補充到，王立軍素有“竊聽狂”的名聲。

除了犯罪團夥嫌疑人之外，政治人物們也成了監聽的目標。

一位與高層有所聯繫的政治分析家，引用從最近一起吃飯的一位上校處獲得的信息說，薄熙來事實上曾試過監聽所有近年到訪重慶的高級領導人的電話，其中包括政法委書記周永康，據傳，周永康將薄熙來視為自己潛在接班人予以背後支援。

“薄熙來想要把領導人對他是什麽態度搞得一清二楚。”該政治分析家說。

去年的另一個實例是，據兩位記者說，截取胡錦濤辦公室與重慶政法委書記劉光磊間的通話的行為曾被抓到過。被王立軍替換下警察局長職務的劉光磊，在80年代胡錦濤主政貴州時，曾在其手下任職。

或許更令薄熙來和王立軍不安的是中紀委不斷加碼的審查，該政治分析家引述中紀委的信源說，從2012年初，四個獨立調查組駐點重慶，其中兩個是隱蔽的。據數位黨內學者指出，調查的其中一條線涉及去年遼寧被揭露的一起賄警案中，王立軍所扮演的可能角色的問題，他曾任遼寧省警察局長。

除了作為例行檢查，目前尚不明確致電胡錦濤的紀委官員——監察部長馬馼——爲什麽會在重慶。她在國賓館用以聯絡胡錦濤的高保安通信線路被薄熙來下令監聽。那通電話的內容不得而知，但很有可能並不是什麽關鍵內容。大多數的電話通信是如此之不安全，以致重要信息往往只會當面或以文字傳達。

不管蓄意與否，北京被薄熙來監聽胡錦濤的作為激怒了，隨之下令中央安全和紀律調查員們向他的警察局長開火，警長先生在此後數月的審查中首當其衝。

“薄熙來想要把責任推給王立軍，”一名黨報資深編輯說，“王立軍不可能敢說這是薄熙來干的。”

然而就在逃離重慶之前，據一位與薄熙來有所聯繫的黨內學者所說，王立軍曾向調查委員會遞交了兩份舉報材料，第一份是匿名的，第二份是實名的。

兩份材料都稱薄熙來曾“與黨中央作對”，包括監聽中央領導人。調查薄熙來的指令在那時就下達了。薄熙來事後知道了這些指控，他在被免職前不久曾對該學者說，他認為自己可以頂得住王立軍的指控。

王立軍不被認為曾在美國大使館里談到過監聽的問題。取而代之的是，他聚焦于不那麼賊喊捉賊地控訴薄妻策劃殺害了尼爾·伍德。

但有消息源稱，薄王二人的緊張關係達到頂峰是在於，薄熙來發現王立軍也監聽了他和他的妻子。在王立軍2月被捕以後，薄熙來扣押了王立軍的監聽專家，從遼寧調來的重慶渝北區警察局長王鵬飛。

黨的內部報告指出，黨將竊聽視為薄熙來最為嚴重的罪行。3月中出爐的一份初步起訴書控訴，薄熙來通過收集有關其它領導人的情報破壞了黨的團結。

然而，黨的官員稱將竊聽問題公開的破壞力過於巨大。在薄熙來最終被起訴的時候，竊聽預計不會被提及。“可以被公開的事情就是經濟問題和謀殺案，”據上訴資深政府媒體口徑官員稱，“這就足夠擺平輿論問題了。”

Ousted Chinese Leader Is Said to Have Spied on Other Top Officials

BEIJING — When Hu Jintao, China’s top leader, picked up the telephone last August to talk to a senior anticorruption official visiting Chongqing, special devices detected that he was being wiretapped — by local officials in that southwestern metropolis.

The discovery of that and other wiretapping led to an official investigation that helped topple Chongqing’s charismatic leader, Bo Xilai, in a political cataclysm that has yet to reach a conclusion.

Until now, the downfall of Mr. Bo has been cast largely as a tale of a populist who pursued his own agenda too aggressively for some top leaders in Beijing and was brought down by accusations that his wife had arranged the murder of Neil Heywood, a British consultant, after a business dispute. But the hidden wiretapping, previously alluded to only in internal Communist Party accounts of the scandal, appears to have provided another compelling reason for party leaders to turn on Mr. Bo.

The story of how China’s president was monitored also shows the level of mistrust among leaders in the one-party state. To maintain control over society, leaders have embraced enhanced surveillance technology. But some have turned it on one another — repeating patterns of intrigue that go back to the beginnings of Communist rule.

“This society has bred mistrust and violence,” said Roderick MacFarquhar, a historian of Communist China’s elite-level machinations over the past half century. “Leaders know you have to watch your back because you never know who will put a knife in it.”

Nearly a dozen people with party ties, speaking anonymously for fear of retribution, confirmed the wiretapping, as well as a widespread program of bugging across Chongqing. But the party’s public version of Mr. Bo’s fall omits it.

The official narrative and much foreign attention has focused on the more easily grasped death of Mr. Heywood in November. When Mr. Bo’s police chief, Wang Lijun, was stripped of his job and feared being implicated in Bo family affairs, he fled to the United States Consulate in Chengdu, where he spoke mostly about Mr. Heywood’s death.

The murder account is pivotal to the scandal, providing Mr. Bo’s opponents with an unassailable reason to have him removed. But party insiders say the wiretapping was seen as a direct challenge to central authorities. It revealed to them just how far Mr. Bo, who is now being investigated for serious disciplinary violations, was prepared to go in his efforts to grasp greater power in China. That compounded suspicions that Mr. Bo could not be trusted with a top slot in the party, which is due to reshuffle its senior leadership positions this fall.

“Everyone across China is improving their systems for the purposes of maintaining stability,” said one official with a central government media outlet, referring to surveillance tactics. “But not everyone dares to monitor party central leaders.”

According to senior party members, including editors, academics and people with ties to the military, Mr. Bo’s eavesdropping operations began several years ago as part of a state-financed surveillance buildup, ostensibly for the purposes of fighting crime and maintaining local political stability.

The architect was Mr. Wang, a nationally decorated crime fighter who had worked under Mr. Bo in the northeast province of Liaoning. Together they installed “a comprehensive package bugging system covering telecommunications to the Internet,” according to the government media official.

One of several noted cybersecurity experts they enlisted was Fang Binxing, president of Beijing University of Posts and Telecommunications, who is often called the father of China’s “Great Firewall,” the nation’s vast Internet censorship system. Most recently, Mr. Fang advised the city on a new police information center using cloud-based computing, according to state news media reports. Late last year, Mr. Wang was named a visiting professor at Mr. Fang’s university.

Together, Mr. Bo and Mr. Wang unleashed a drive to smash what they said were crime rings that controlled large portions of Chongqing’s economic life. In interviews, targets of the crackdown marveled at the scale and determination with which local police intercepted their communications.

“On the phone, we dared not mention Bo Xilai or Wang Lijun,” said Li Jun, a fugitive property developer who now lives in hiding abroad. Instead, he and fellow businessmen took to scribbling notes, removing their cellphone batteries and stocking up on unregistered SIM cards to thwart surveillance as the crackdown mounted, he said.

Li Zhuang, a lawyer from a powerfully connected Beijing law firm, recalled how some cousins of one client had presented him with a full stack of unregistered mobile phone SIM cards, warning him of local wiretapping. Despite these precautions, the Chongqing police ended up arresting Mr. Li on the outskirts of Beijing, about 900 miles away, after he called his client’s wife and arranged to visit her later that day at a hospital.

 “They already were there lying in ambush,” Mr. Li said. He added that Wang Lijun, by reputation, was a “tapping freak.”

Political figures were targeted in addition to those suspected of being mobsters.

One political analyst with senior-level ties, citing information obtained from a colonel he recently dined with, said Mr. Bo had tried to tap the phones of virtually all high-ranking leaders who visited Chongqing in recent years, including Zhou Yongkang, the law-and-order czar who was said to have backed Mr. Bo as his potential successor.

“Bo wanted to be extremely clear about what leaders’ attitudes toward him were,” the analyst said.

In one other instance last year, two journalists said, operatives were caught intercepting a conversation between the office of Mr. Hu and Liu Guanglei, a top party law-and-order official whom Mr. Wang had replaced as police chief. Mr. Liu once served under Mr. Hu in the 1980s in Guizhou Province.

Perhaps more worrisome to Mr. Bo and Mr. Wang, however, was the increased scrutiny from the party’s Central Commission for Discipline Inspection, which by the beginning of 2012 had stationed up to four separate teams in Chongqing, two undercover, according to the political analyst, who cited Discipline Inspection sources. One line of inquiry, according to several party academics, involved Mr. Wang’s possible role in a police bribery case that unfolded last year in a Liaoning city where he once was police chief. 

Beyond making a routine inspection, it is not clear why the disciplinary official who telephoned Mr. Hu — Ma Wen, the minister of supervision — was in Chongqing. Her high-security land link to Mr. Hu from the state guesthouse in Chongqing was monitored on Mr. Bo’s orders. The topic of the call is unknown but was probably not vital. Most phones are so unsafe that important information is often conveyed only in person or in writing.

But Beijing was galled that Mr. Bo would wiretap Mr. Hu, whether intentionally or not, and turned central security and disciplinary investigators loose on his police chief, who bore the brunt of the scrutiny over the next couple of months.

“Bo wanted to push the responsibility onto Wang,” one senior party editor said. “Wang couldn’t dare say it was Bo’s doing.”

Yet at some point well before fleeing Chongqing, Mr. Wang filed a pair of complaints to the inspection commission, the first anonymously and the second under his own name, according to a party academic with ties to Mr. Bo.

Both complaints said Mr. Bo had “opposed party central” authorities, including ordering the wiretapping of central leaders. The requests to investigate Mr. Bo were turned down at the time. Mr. Bo, who learned of the charges at a later point, told the academic shortly before his dismissal that he thought he could withstand Mr. Wang’s charges.

Mr. Wang is not believed to have discussed wiretapping at the United States Consulate. Instead, he focused on the less self-incriminating allegations of Mr. Bo’s wife’s arranging the killing of Mr. Heywood.

But tensions between the two men crested, sources said, when Mr. Bo found that Mr. Wang had also wiretapped him and his wife. After Mr. Wang was arrested in February, Mr. Bo detained Mr. Wang’s wiretapping specialist from Liaoning, a district police chief named Wang Pengfei.

Internal party accounts suggest that the party views the wiretapping as one of Mr. Bo’s most serious crimes. One preliminary indictment in mid-March accused Bo of damaging party unity by collecting evidence on other leaders.

Party officials, however, say it would be far too damaging to make the wiretapping public. When Mr. Bo is finally charged, wiretapping is not expected to be mentioned. “The things that can be publicized are the economic problems and the killing,” according to the senior official at the government media outlet. “That’s enough to decide the matter in public.”