Farouk Arnaz – Businessman Ary Muladi on Tuesday was interrogated by Indonesia's National Police, a day after he was questioned at length by investigators from the Corruption Eradication Commission.

Both the anti-graft commission, known as the KPK, and the police are racing to obtain evidence in the massive corruption scandal that has rocked the nation.

Both the KPK and police consider Ary a key witness in a plot allegedly designed to weaken the commission and pin extortion charges on two of its deputy commissioners.

One of the people allegedly involved in the plot was Anggodo Widjojo, brother of businessman Anggoro Widjojo, who the KPK was investigating for alleged corruption.

"My client was invited by the police to provide them with information only as a witness, most likely against Anggodo Widjojo. So far, police have not declared Anggodo a suspect," Petrus Selestinus, Ary's lawyer, said.

Petrus said police were attempting to collect evidence to declare Anggodo a suspect for obstruction of justice and defamation against the president. He added that other charges being investigated included extortion.

Petrus referred to the 67 separate wiretapped conversations secretly recorded by the KPK, which were played during a recent hearing at the Constitutional Court.

The conversations, which included several between Anggodo and a number of people from the National Police and the Attorney General's Office (AGO), described a conspiracy allegedly hatched to undermine the KPK.

A voice on the tapes also indicated that President Susilo Bambang Yudhoyono had allegedly given his support to Anggoro.

Ary previously told the National Police that he channelled Rp 5.1 billion ($545,700) to several executives at the KPK from long-time friend Anggodo. He later retracted this statement, saying that it was fabricated.

Ary has been declared a suspect for receiving money from Anggodo to allegedly pay off KPK officials and pocketing a fee for his services as a case broker.

On Monday, Sugeng Teguh Santoso, another lawyer representing Ary, requested that the KPK take over the ongoing police investigation of Anggodo for attempted bribery and obstructing a KPK investigation.

Sugeng said Ary has also sought the protection of the KPK because police have allegedly been pressuring Ary into saying he had channeled the funds directly to the KPK deputies.