The whistle-blower responsible for exposing the sex video scandal that has toppled six local Party and government officials and another five State-owned enterprise executives in Chongqing declined Monday to hand over more evidence on the case to Chongqing police, citing concerns over the safety of his source.

Zhu Ruifeng, a Beijing-based blogger with the Hong Kong-registered anti-corruption website jdwsy.com, walked out of a Beijing police station Monday after a seven-hour negotiation session with two Chongqing police officers.

Zhu told the Global Times that he had rejected the request made by the two officers, who had been seeking more tapes involving other high-ranking officials.

"I also turned down their demand for the original version of those already exposed clips, for the safety of the person from Chongqing's police bureau who fed me the information," said Zhu, adding that he is not ready to publish the remaining evidence, as time is needed to authenticate them.

The negotiations came after Zhu claimed some local officials involved in the scandal haven't yet been netted and accused local police of a coverup and destroying evidence.

Sun Lida, president of a State-owned construction company in Chongqing, was named by Zhu as the latest executive to be implicated in the scandal. Sun still holds his position.

Zhu posted five entries on his Sina Weibo Sunday night saying that five police officers were about to enter his home in Beijing's Xicheng district. Zhu also said that the officers searched his ex-wife's apartment in Beijing on Sunday night.

In a statement that was posted hours later on both Sina Weibo and his website, Zhu entrusted a group of six lawyers to represent him, and claimed that if he was ever detained by the Chongqing police he would exercise his right to silence. He also said that any action aimed at replacing the lawyers he had appointed was invalid.

Four lawyers, Zhang Kai, Cheng Hai, Li Heping and Wang Peng, showed up to accompany him to the police station Monday morning in a conciliatory move to show he was willing to negotiate with the two officers.

The officers, who belong to the investigation team behind the scandal that has recently shaken the municipality, "threatened to charge Zhu for hiding evidence," Li told the Global Times.

The two Chongqing officers were not available for comment on Monday.

In an interview with local news portal cqnews.net, the head of the investigation team confirmed that officers have been sent to Beijing to involve Zhu in the probe. The officer also said that Zhu is obligated to cooperate with the police and provide evidence.

A press officer surnamed Zhang from Chongqing's public security bureau told the Global Times that the police are doing all they can in terms of the investigation and will inform the public of any updates in a timely manner.

Si Weijiang, a Shanghai-based lawyer, told the Global Times there is no crime of withholding evidence, and that the process to compel Zhu to be a witness is not clear. The police have no right to forcibly request the evidence, he said.

Zhu became famous after posting the secretly-shot sex video in November showing Lei Zhengfu, the former Party chief of Chongqing's Beibei district, having sex with a young woman at a hotel room years ago.

The scandal claimed Lei's career in the Party, before he was sent to the municipal discipline authorities for investigation.

The municipal government said Thursday that during the probe into Lei's illegal deeds, discipline inspectors also busted a criminal network suspected of using secretly filmed sex videos to extort officials.

Ten more officials were removed from their posts for allegedly appearing in the videos, said statements from the municipal government.