JAKARTA - Indonesian authorities are holding a securities tycoon in custody over a high-profile fraud case on Friday (April 22), a day after Singapore authorities "removed" him from the republic.

Mr Hartawan Aluwi, 54, had fled Indonesia for Singapore in 2008, after he was named a suspect along with several others for allegedly misusing government's money amounting to Rp 6.7 trillion (S$685.5 million) to bail out the now-defunct Bank Century during the 2008 global financial crisis.

The controversial rescue was to prevent a systemic risk or collapse of Indonesia's financial services industry.

Mr Hartawan had used a number of accounts in PT Antaboga Delta Sekuritas Indonesia, a securities firm where he was its president commissioner, to hide money sent by Bank Century founder Mr Robert Tantular, local media reported.

On Thursday (April 21), the Singapore Immigration and Checkpoints Authority took Mr Hartawan into custody, after "the Controller of Immigration cancelled his entry permit and declared his presence in Singapore to be unlawful", a Ministry of Home Affairs (MHA) said in a statement.

"He was removed from Singapore on the same day", it added.

Indonesian police investigators had flown together with him from Singapore to Jakarta's Soekarno-Hatta airport on Thursday night, national police spokesman Boy Rafli Amar told reporters on Friday.

Indonesia and Singapore have signed an extradition treaty, but Indonesian lawmakers have yet to ratify it in Parliament.

Mr Boy said Mr Hartawan's passport had expired in 2012 and his Singapore permanent residency status was revoked around February this year, providing "an opportunity for local authorities to bring him back".

"This is really a coordination with support from the Singapore government towards our search efforts," he added.

Singapore Home Affairs Minister K Shanmugam had considered Mr Hartawan to be an "undesirable immigrant... due to his involvement in fraudulent investment schemes and money laundering activities", MHA said.