HONG KONG • An alleged triad boss known as "Shanghai Boy" has been arrested after arriving at Hong Kong airport from Thailand.

Mr Kwok Wing Hung was detained on Thursday night for "conspiracy to commit criminal intimidation, conspiracy to wound with intent, and conspiracy to blackmail", police said in a statement yesterday.

Famed for his ever-present 70s-style sunglasses and swept-forward bowl haircut, Mr Kwok, 58, had dropped off the radar for seven months, according to local media.

He had been put on a wanted list and was arrested at the airport by officers from the Organised Crime and Triad Bureau, the South China Morning Post reported.

A video from the Oriental Daily showed Mr Kwok, wearing a dark suit and being escorted by officers into a police van at the city's airport after reportedly arriving from Phuket.

The controversial businessman's public profile rose in 2012 after he was reportedly seen dining with a campaign director for the city's current leader Leung Chun Ying - then a candidate for chief executive.

That led to questions over whether Mr Leung and his team were in collusion with the triads.

Mr Kwok was back in the headlines in December last year after reports that he had been punched in the face by a mystery attacker while having afternoon tea at Hong Kong's Peninsula Hotel. After treatment at a private hospital, Mr Kwok brushed off the incident, saying he had bumped into a table.

The attack was related either to a dispute over his mistress, or to financial problems with his Macau business, reports said.

Days after the attack, Mr Kwok called a much-anticipated press conference but failed to show up.

During mass pro-democracy protests in 2014, the police and the government were forced to deny allegations that they were working with criminals, after masked thugs attacked protesters at a demonstration camp in Mongkok - a working- class district known for its triad gangs.

AGENCE FRANCE-PRESSE