Colonel Piyawat Pinket, spokesman for the Department of Special Investigation (DSI), said Tun Tex Hai, aka "Valentino" and his wife Suwaphat Kheeree-phon were released on bail of Bt600,000 each.

The couple were arrested on Thursday night at their home in Phuket's Muang district as prime suspects for illegally acquiring more than 1,000 rai on the island in 1994.

After taking over the case from local police late last year, the DSI found the couple paid corrupt land officials to have title deeds illegally issued on a 300-rai plot of public land and part of a forest reserve, a DSI report said. The report said it also found that after 1994, more title deeds have been issued on other public and restricted areas covering another 700 rai.

The DSI report alleged that the couple used the deeds as collateral for a number of mortgage loans totalling more than Bt400 million. The mortgages were granted by two now-defunct financial institutions in which Tun served as a director.

Pol General Tawee Sodsong, DSI's deputy director-general, said he had asked the Anti-Money Laundering Office to investigate the process of granting the loans to expand the case and arrest more of those who might be involved.

Piyawat said a police investigative team is now on the hunt for another prime suspect, Tun Chi Kieng, a Malaysian man, who was reported as a broker for the land-grabbing scheme.

The other three suspects, Krachang, Boonlert Kheeree-phon and Major Nakhon Thongmee had contacted police, saying that they would report to them tomorrow or on Tuesday, said Piyawat.