A US politician has been arrested in Hong Kong for having a gun in his carry-on luggage on a flight.

Jeff Wilson, a Republican senator from Washington state, was arrested at Hong Kong International Airport after arriving from San Francisco.

He appeared in court on Monday charged with carrying a firearm without a licence, and was released on bail.

Mr Wilson said it was "an honest mistake"and he expected it all would be resolved soon.

In a statement on his website, the senator said he was travelling with his wife on the first leg of a five-week holiday in Southeast Asia.

He said the weapon was not detected by airport security in Portland, Oregon, and he only discovered it when he was rummaging for chewing gum on the flight from San Francisco to Hong Kong.

Hong Kong's public broadcaster, RTHK, reported that customs officers found the revolver when conducting a bag check but the senator says he declared the item to customs as soon as he landed.

The US Transport Security Administration (TSA) told the BBC that they were aware of the incident and they were investigating the matter.

The senator said the gun was not registered in Hong Kong, but was registered in Washington state and that he holds a concealed pistol licence.

In Hong Kong, carrying a firearm without a licence is punishable by up to 14 years in prison and a fine of HK$100,000 (£10,400).

Mr Wilson appeared at Shatin Magistrates' Court on Monday accompanied by his wife and two other men.

He was released on cash bail of HK$20,000 (£2,100) and ordered to hand over his passport and return on Monday, 30 October.

The TSA says firearms cannot be taken in carry-on bags on international or domestic flights. They can be checked in, but the carrier must ensure they are locked in containers and declared to the airline while checking in.

The penalty for bringing a firearm to a TSA checkpoint may be as high as $15,000 (£12,300).

Hong Kong's Customs and Excise Department said in an emailed response to the BBC that they could not comment on the case since legal proceedings are under way.

The BBC has approached the US consulate in Hong Kong for comment.