Heru Andriyanto, Jakarta – The job of any defense lawyer is to prove his client innocent, or failing that to ensure the lightest punishment possible.

But that is not the case for veteran lawyer Adnan Buyung Nasution in his handling of the case of the country's most famous former tax official, Gayus Tambunan.

Adnan has been vocal in his criticism of the police and prosecutors for "reducing the judicial mafia scandal to a minor tax scam involving an unknown company" and for "prosecuting the Rp 570 million tax scam while turning a blind eye to the trail of Gayus's personal wealth of around Rp 100 billion."

Officials' handling of the Gayus case has angered anti-graft campaigners and increased the pressure on the government to let the Corruption Eradication Commission (KPK) take over from the police and prosecutors.

On Thursday, during the commemoration of International Anti-Corruption Day, the Indonesian Survey Institute (LSI) released a survey showing public approval of President Susilo Bambang Yudhoyono's handing of the campaign against graft had reached its lowest level since he took office in 2004.

The widely reported Gayus saga might have contributed to that decline, said Danang Widoyoko, chairman of the nongovernmental group Indonesia Corruption Watch. "The Gayus case is being handled by police and prosecutors, who work under the president. When the case develops into never-ending scandals, people begin to blame the president," he said.

Gayus has repeatedly said that he received the equivalent of Rp 35 billion ($3.9 million) from three companies under the Bakrie Group – Kaltim Prima Coal, Bumi Resources and Arutmin – but he is being tried for allegedly helping a small company, Surya Alam Tunggal, receive a state refund worth Rp 570 million using false claims while he was a mid-level tax official.

"Have you ever heard of Surya Alam Tunggal? The case started as a major scandal, but police and prosecutors worked in such a way that the court is only trying a trivial case," said Adnan, who also serves as adviser to the president on legal affairs.

"We need to return to the old system that allowed judges to reject a case or order prosecutors to improve the indictment before the trial could start. I agreed to advocate this case because I saw it as providing momentum to expose the mafia inside the tax office, the prosecutor's office and the police. But things are very different now."

Gayus is standing trial for a second time because in his first trial in Tangerang, prosecutors ignored the Rp 28 billion in his personal bank accounts and presented a minor charge of embezzling just Rp 370 million from another small company. Gayus reportedly bribed law enforcement officials to ensure he faced only the embezzlement charge, for which he was acquitted by the Tangerang court.

Even Gayus seems puzzled by the handling of his case. At Wednesday's hearing, Gayus told the court he couldn't understand why the Surya case had landed him a criminal charge.

"My job was to verify objections and complaints by taxpayers and deliver recommendations to my superiors. My team and I handled lots of cases like this. We once approved [a refund] of Rp 100 billion without any problem. So, why Surya?" he told the South Jakarta District Court.

A trip to Bali for a tennis tournament and the claims against the Bakrie Group companies are just two of the scandals that have emerged since Gayus was detained in March.

A senior official at the Attorney General's Office has been reported to the police for allegedly leaking Gayus's sentencing demand document during his first trial, and nearly a dozen police officers were named suspects for guarding his empty cell on numerous occasions.

In the wake of his first trial, a police general ordered BCA and Panin banks to lift the freeze on Gayus's 21 accounts, and the Rp 28 billion they held is now nowhere to be found.

Gayus also admitted to meeting with the presiding judge in that first trial to discuss a bribe only minutes before his acquittal. The judge, Muhtadi Asnun, was sentenced on Thursday to just two years in jail.

A mid-ranking police officer in charge of Gayus's first case met with him before the formal investigation began and told him "we are eager to help," and when Gayus set up a bogus business deal to launder the money, the officer, Arafat Enanie, even advised him.

The Gayus trial also revealed that middlemen played a role between corporate taxpayers and the tax office, which Gayus described as "a normal practice."

Too many things have gone wrong in the Gayus case and what police and prosecutors are doing now is only making things worse, said Boyamin Saiman, chairman of the Indonesian Anti-Corruption Society (Maki).

"The president has declared that his government is against corruption, but his policies and actions do not reflect his words," he said. "Anti-graft measures often become a tool to pressure political opponents. In the Gayus case, the gun is aimed at [Golkar Party chairman] Aburizal Bakrie."

Boyamin said the KPK should take over the Gayus case to ensure a fair and independent investigation into whoever is involved in the scandal, because "what's at stake here is not the president's reputation, but the country's justice system."