Jakarta. The Corruption Eradication Commission, or KPK, detained former high-ranking tax official Rafael Alun Trisambodo on Monday for allegedly colluding with a tax consultant firm to enrich himself in a serious conflict of interest while he was still working at the Finance Ministry's taxation directorate.

The commission also ordered Rafael to prove that the cash in foreign currencies amounting to Rp 32.2 billion ($2.2 million) investigators seized from safe deposit boxes registered in his name was derived from lawful sources, KPK Chairman Firli Bahuri told a news conference in Jakarta.

Rafael has a share in a number of companies including accounting and tax consultant firm Artha Mega Ekadhana, Firli said.

"When taxpayers found themselves in trouble related to their tax payment, RAT allegedly recommended AME to help them," Firli said, referring to Rafael and the company by initials.

Rafael was installed as a tax investigator in 2005 which gave him the authority to investigate and pursue taxpayers for tax evasion.

The suspect allegedly accepted at least $90,000 from Artha Mega while serving as a tax official at the East Java Tax Office in 2011.

KPK investigators recently seized cash in euros and Singapore and US dollars worth the equivalent of Rp 32.2 billion kept in bank safe deposit boxes, Firli said.

In a separate search at the suspect's home on Jalan Simprug Golf, South Jakarta, investigators confiscated luxury items such as wallets, belts, jewelry, bags, a bicycle, and an unspecified amount of cash in rupiah.

Rafael was named a corruption suspect last week, only days after the Finance Ministry fired him for undeclared assets and underreporting his wealth.