Keighley’s newly-elected UKIP town councillor is in the eye of a political storm caused by late-night messages on his Facebook page in which he implies enjoying an adulterous affair with a married mother in the town.

Samuel Fletcher only won his seat last month, but yesterday he became the focus of attention after details of his apparent revelations were made public on the internet.

And now the claims about his online behaviour are being investigated by UKIP itself, which is “concerned by what it has seen”.

Coun Fletcher, 22, made a late-night Facebook posting on New Year’s Day which were then copied and placed on a blogsite run by a Conservative student.

And among many messages, it is claimed that bachelor Mr Fletcher revealed he had extra-marital sex with a woman he described as “a good salt of the earth Keighley lass”.

Speaking yesterday, Coun Fletcher, who represents the Bracken Bank and Ingrow ward, acknowledged he had posted the comments – but denied they were true.

“The comments about the woman being married were untrue and I made that part up to protect the identity of the woman I was talking about,” he said. “The woman involved was not married.”

Coun Fletcher said he had posted the comments two nights ago during conversations with assorted people.

“Some of those I talk with are friends and other are just people who come on to talk and might actually be on “fishing trips,” he said.

Coun Fletcher also referred to UKIP’s Nigel Farage as “leader of UKIP in name only” and says the party makes decisions collectively.

However, when asked to explain the comment, he said: “That is how Nigel has described himself on many occasions and that is how the party is run.”

A UKIP spokesman told the Telegraph & Argus last night: “The party is concerned by what it has seen and is currently investigating.”

Coun Fletcher is also UKIP’s prospective candidate to contest the Keighley Central ward in the elections for Bradford Council in May.