The Department of Special Investigation will take up the triads case involving Chinese businessman Chaiyanat "Tuhao" Kornchayanant, Justice Minister Somsak Thepsutin said on Thursday.
The minister said it would be treated as a special case, deserving of being handled by the DSI, because it was complicated, affected national security and involved a large amount of assets.
Mr Somsak said authorities had impounded assets worth about 3.21 billion baht linked to Tuhao, who had 4-5 groups of people behind him. These people had foreign passports and were suspected of moving funds into Thailand. The DSI had their passport numbers and was tracking them down.
The Office of the Narcotics Control Board was about to impound another 1.22 billion baht of assets for examination in relation to Tuhao, the minister said.
Thanakrit Jit-areerat, secretary to the justice minister, said the impounded assets were in the possession of both individuals and companies.
The DSI would call the individuals and directors of the companies in for questioning within two weeks, and would press charges within a month, he said.
It would also ask the Bank of Thailand to support its investigation into their financial transactions, the secretary said.
Tuhao turned himself in to Bangkok police on Nov 23 to answer allegations of involvement in the illicit drug trade.
He was wanted on an arrest warrant issued by the Bangkok South Criminal Court for collusion in the drug trade and for illegal possession of a psychotropic substance with the intent to sell. He denied the charges.
His surrender followed searches at two locations in Bangkok -- a luxury house on Rama V Road and a luxury hotel in downtown Bangkok -- believed to be his hideouts.
On Oct 26, police stormed Jinling, which operated illegally as a nightclub in three adjacent buildings on Charoen Rat Road in Yannawa district, and 104 customers, 99 of them Chinese nationals, tested positive for drug use.
Tuhao was reported to be the owner of the businesses in the complex.
He was also suspected of involvement with a scheme organizing Chinese people to travel to Thailand for illegal purposes.
Tuhao is known to have made a three-million-baht donation to the ruling Palang Pracharath Party.
He received Thai nationality as he has a Thai wife who is a police colonel reported to be with the police foreign affairs sub-division and a niece of a former commissioner of the Royal Thai Police.
On Wednesday the Office of the Attorney-General said it would also investigate cases related to Tuhao.