A senior Barnet politician is under investigation over claims he lied to full council about his attendance at the meetings of an outside body.

Councillor Dean Cohen, Barnet Borough Council's cabinet member for environment, failed to explain in the council chamber last week that he had not attended the two previous meetings of the North London Waste Authority (NLWA) – at which major decisions were being taken concerning the borough.

Barnet Council confirmed this week it received a complaint from Cllr Cohen’s predecessor, expelled Conservative Councillor Brian Coleman, who claims his former Tory colleague lied to members.

The allegations relate to a question asked by Labour’s group leader Councillor Alison Moore, who quizzed the cabinet member on which way Barnet’s representatives had voted on the subject of procurement for waste disposal in the borough.

Councillor Cohen said the voting record of himself and deputy leader Dan Thomas were confidential, and “swerved the question” according to Councillor Coleman.

But Golders Green representative Cllr Cohen insists he would have revealed he was not there if he had been asked directly.

He said: “The question was how did representatives of the borough vote – not how did I vote. I was advised that the meeting was private and confidential and so my answer was appropriate. If I had been asked directly, I would have said I wasn’t there. There was no lie.”

Councillor Cohen’s non-attendance at the meeting in September came due to his commitments to the Jewish holiday of Shemini Atzeret.

Authority members are expelled from the committee if they fail to attend a meeting in more than six months, and the committee was forced to approve an extension for Councillor Cohen, who had also missed the previous meeting.

He said: “It was a very important vote but the borough was represented adequately by Councillor Thomas. I have to put my religious practices and my family before anything else and I will not jeopardise that.”

But Councillor Coleman, who previously sat as a member on the NLWA, insists the extension given for Councillor Cohen’s non-attendance is “unheard of” for an environment portfolio holder.

He said: “This was a vital meeting at which they were discussing the future of waste disposal in the borough and a £36million contract – something he is in charge of.

“He lied to council by failing to tell us he was not there and that is unforgiveable. That is the key issue – never mind his non-attendance. It is a disgrace and a breach of the code of conduct.

“It is the most outrageous behaviour from a councillor I have witnessed at a council meeting.”

Councillor Moore believes it would have been “the honest thing to do” for Councillor Cohen to inform the chamber he was not at the meeting, but she stopped short of backing up Councillor Coleman’s claims.

She said: “I didn’t specifically ask if he was at the meeting but it is fair to say he didn’t volunteer that information, which would have been the honest thing to do.

“I don’t believe he lied, and his non-attendance was pretty clear on the NLWA website when I looked.”

On the complaint by Councillor Coleman, Councillor Cohen added: “I have nothing to hide. It is up to him if he wants to report me – it is not in my nature to launch any personal attacks.”