A controversial member of the ruling Democrat Party is facing claims of impropriety just a day after being sworn into Prime Minister Chuan Leekpai's new Cabinet. Transport Minister Suthep Thaugsuban returned from Phuket on Sunday with five models on board a corporate jet to celebrate his swearing in to the Cabinet the previous day, Khao Sod reported yesterday. The jet belonged to the owner of a major transport firm - a fact which has alarmed several senior party members. The day before, Mr Chuan had lectured his new Cabinet on the need for austerity and particularly the need to avoid lavish parties as the new Government grappled to solve Thailand's financial crisis. Mr Chuan has reportedly warned Mr Suthep to be more careful of his public conduct in future. Senior party sources said they were more concerned at the link to the jet's owner than his alleged companions. Mr Suthep has denied any misconduct, saying he had travelled to Phuket to give a political address to the Muslim community and visit his daughters, not simply for a celebration. He said he took the offer to return on the charter flight to quickly return to Bangkok and had no interest in partying. Mr Suthep, an MP for the southern province of Surat Thani, has been linked to a Phuket land misappropriation scandal that dogged the last days of Mr Chuan's tenure as prime minister in 1995. In an intriguing twist, one of the senior policemen who probed those claims is himself to be investigated for the controversial killing of six suspected drug dealers last year. The high-profile case sparked concern at the conduct of the Interior Ministry during the rule of former prime minister General Chavalit Yongchaiyudh after it emerged the six had been shot while handcuffed. The change of government may have set off new investigations into the role of General Salang Bunnag, who claimed the Democrats used the shooting to divert attention away from Mr Suthep.