Japanese authorities have arrested a former senior policeman from Thailand for possessing a loaded gun at a Tokyo airport, officials said today. Comronwit Toopgrajank, a former Bangkok police chief, was detained on Monday at Narita airport as he tried to leave the country, a police spokesman said. Officials stationed at the airport discovered a revolver with five live rounds in the 60-year-old’s suitcase and arrested him on the spot on suspicion of violating gun laws, the spokesman said. The suspect told police “the gun was his own and was a gift from a friend, and that he had forgotten he had put it inside the suitcase”, the official said. “He entered Japan on June 19, and said he visited a waste incineration plant as part of a group of some 80 people,” the spokesman added. A Thai embassy official said Comronwit was being quizzed by prosecutors. Comronwit headed the police in Thailand’s capital between July 2012 and May last year, the same month Thailand’s generals seized power in a coup. He retired later that year. Thai junta chief Prayuth Chan-ocha said today that he had ordered officials at the country’s biggest airport Suvarnabhumi to investigate whether Comronwit was able to take the pistol through security before flying to Japan. “I have ordered the investigation to look at whether he can smuggle such a thing on board and whether he passed through X-ray machines,” he told reporters. Such a security breach, if proven, would be a major embarrassment for Thailand at a time when its aviation industry is under increased scrutiny. Last week, the International Civil Aviation Organization “red-flagged” Thailand after it failed to meet a deadline to address a “significant safety concern” about how air operators are certified. Analysts say that move could prompt further scrutiny by aviation bodies in the United States and Europe as well as make it harder for Thai airlines to find insurance or lease new aircraft. Prayut has vowed to meet the ICAO’s demands. Comronwit’s detention also comes a fortnight after five Thais were detained at Lahore airport in Pakistan after one of them tried to board a plane with a pistol and ammunition. So far they had not been linked to any insurgent groups in Thailand. While Japanese police do carry guns, Japan has very strict firearms control laws and few people possess weapons or have come into contact with them. Thailand’s police are armed and the country has one of Asia’s highest gun murder rates.