By Arlina Arshad

JAKARTA - Indonesia's top detective quit Thursday after wiretap phone recordings implicated him in an alleged plot to falsely imprison anti-graft investigators, in a scandal that has appalled the nation.

Three-star Police General Susno Duadji, the national chief of detectives, submitted his resignation two days after the recordings were played in a nationally televised session of the Constitutional Court.

"Today he has tendered his resignation. The national police has received his letter," police spokesman Nanan Soekarna told a press conference amid calls for police chief Bambang Hendarso Danuri to follow suit.

Deputy Attorney General Abdul Hakim Ritonga, equally implicated in the alleged plot, is also expected to resign in line with a request from President Susilo Bambang Yudhoyono for all those involved to stand down.

"I've advised the police chief and the attorney general to suspend those whose names were mentioned in the tape recordings and discharge them from their duties," Yudhoyono told a cabinet meeting earlier Thursday.

Duadji was allegedly at the centre of a conspiracy involving senior police, prosecutors and a corrupt businessman to fabricate criminal charges against two deputy chairmen of the Corruption Eradication Commission (KPK).

The commissioners, Chandra Hamzah and Bibit Samad Riyanto, were arrested by police last week but were released Tuesday after the KPK's wiretap recordings exposing the apparent conspiracy were played in court.

Attorney General Hendarman Supandji, who has ignored repeated calls to resign over corruption within his department, told reporters that Ritonga had informed him of his intention to step down.

But the resignations of Duadji and Ritonga may not be enough to calm public anger over the scandal, which has lifted the lid on what Indonesians call the "Court Mafia", or corrupt collusion between the judiciary and the police.

More than 860,000 Indonesians have joined a group on social networking website Facebook supporting the two KPK investigators, who are still facing charges of extortion and abuse of power that the police refuse to drop.

The tapes have sparked protests across the country of 234 million people, where many see the KPK as the only clean institution and the police as rotten with corruption.

Analysts said Yudhoyono, re-elected in July on promises of clean government, was under extreme pressure to prove the sincerity of his much-touted anti-corruption drive.

"It's not enough that only Susno and Ritonga resign, the national police chief and attorney general should also resign if they still want to be respected," University of Indonesia political analyst Arbi Sanit said.

"After they resign, all of them need to be prosecuted legally."

The KPK has made enemies across the spectrum of Indonesian government and administration for its successful corruption prosecutions and its far-reaching powers to wiretap suspects and probe their bank accounts.

But it has given hope to ordinary Indonesians and foreign investors alike in a country that ranks 126 out of 180 on Transparency International's corruption perceptions index for 2008, alongside Honduras and Libya.

Members of a "fact-finding team" appointed by Yudhoyono have demanded the resignations of Duadji and Ritonga and the continuing detention of Anggodo Widjojo, the brother of a KPK suspect whose phone calls to police and prosecutors were played in court.

One of the alleged conspirators is heard whispering that the alleged plot has the support of "RI-1", a reference to Yudhoyono.

Yudhoyono and has angrily denied any involvement.