Tom Allard, Jakarta – A relative of Indonesia's President will spend up to four-and-a-half years in prison for his role in a scandal involving two of the country's pre-eminent institutions, its central bank and parliament.

The prison term for the former deputy governor of the Bank of Indonesia, Aulia Pohan, was more than the maximum sought by prosecutors. "I am shocked. I am suffering," Pohan told a throng of reporters after the verdict yesterday.

Pohan is the father of President Susilo Bambang Yudhoyono's daughter-in-law. The prominent case has boosted the anti-corruption credentials of the Indonesian leader who is contesting his re-election to the presidency.

Pohan said last week his prosecution was politically motivated, saying "if I were not father-in-law of the President's son, I would not be tried in this court."

Pohan and three other senior Bank of Indonesia officials were found guilty of appropriating 100 billion rupiah ($12.4 million) in 2003 from the central bank's coffers to pay off parliamentarians to pass legislation and fund the legal fees of other central bank officials.

Those officials were defending themselves against charges relating to their involvement in the earlier embezzlement of funds earmarked for the bail-out of Indonesia's financial institutions in the wake of the economic collapse of 1997 and 1998.

The decade-long scandal and investigation into the central bank has already led to the imprisonment of two central bank governors and several other senior officials. Another corruption case involving the alleged bribing of politicians – to approve the reappointment of the Bank of Indonesia deputy governor, Miranda Goeltom, has been reopened.

While the wrongdoing of the bankers has been met with the full force of the law, the parliamentarians who took the cash, travellers' cheques and other inducements have got off lightly.

"[The legislator] Hamka Yamdu, who first came out with this case, reported 52 parliamentarians were implicated," said Febriansyah, a researcher at Indonesia Corruption Watch. "But none of them was taken to court, including two who are now ministers in SBY's current cabinet." SBY is the President's nickname.

Indonesia regularly ranks as one of the most corrupt nations on earth and there is no shortage of suspects for its independent Corruption Eradication Commission to pursue.

Pohan feels aggrieved that he was targeted because he did not personally benefit from the transaction that has led to his imprisonment. He has vowed to appeal against the decision.