Police raided a bar on Ratchadaphisek Road which former politician and massage parlour tycoon Chuwit Kamolvisit claimed was operating beyond legal opening hours and selling drugs.

However, officers who inspected the bar said it complied with rules on operating hours and found no signs of drugs being sold.

The raid followed a claim posted by Mr Chuwit on his Facebook page, in which he said the bar has been known to operate until 4am, and that half of its patrons are on drugs.

The bar, he said, is owned by a Chinese national known as "David", whom he said is well-connected in Thailand.

After the raid took place, Mr Chuwit held a press conference to thank the police for their quick response to his tip.

Police have to remain vigilant, he said, as Chinese businessmen are starting to take over what he called "grey" businesses in Thailand, referring to bars, massage parlours and gambling dens.

"The Chinese are unlikely to stick to legal means to run such businesses," he said, before alleging "David" often lobbies politicians and police on their behalf. The officers may have found nothing because the raid took place during a Buddhist holiday, he said.

Mr Chuwit said he will reveal the names of politicians who are known to have ties with Chinese criminal gangs, to help fight corruption in the country.