Farouk Arnaz, Jakarta – The National Police will send officers to Surabaya, East Java, to hunt down the mystery man who allegedly worked as a go-between for rogue tax official Gayus Tambunan and Bakrie Group companies, a police official told the Jakarta Globe on Sunday.

"We'll dispatch officers from our anticorruption unit to look for Imam Cahyo Maliki," said the source, speaking on condition of anonymity. "We understand he's mentally ill and being treated at a psychiatric hospital in Surabaya."

The source added it was important to question Imam in order to clarify claims by Gayus that he took bribes from the companies, partly-owned by the family of Golkar Party chairman Aburizal Bakrie, in exchange for tax breaks.

"We've summoned Imam twice before to appear for questioning, but he has failed to comply," the source said. "We haven't been able to name him a suspect yet due to the lack of evidence, but in order to assure the public that we're taking this case very seriously, we need to go after him."

Imam's name was first mentioned by Denny Indrayana, a presidential adviser. He said Gayus had told him that Imam had helped arrange the transfer of up to $7 million in bribes from the Bakrie companies, including miners Kaltim Prima Coal, Arutmin and Bumi Resources.

Gayus also claimed he had been helped in his dealings with the Bakrie companies by an insider at one of the firms, identified only as Deni, according to Denny.

Imam's older brother, Alif Kuncoro, was sentenced to 18 months in September for bribing a police officer to not name him a suspect in Gayus's original embezzlement trial.

Gayus's lawyer, Adnan Buyung Nasution, welcomed the plan to track down Imam and unravel the case: "[Otherwise] we'll never know for sure where Gayus got his money from," he said.