A local politician is under investigation after it was alleged that he failed to declare a financial interest.

The Office of the Parliamentary Commissioner for Standards has confirmed that an inquiry is under way into Peter Lilley, MP for Hitchin and Harpenden, after he failed to declare an interest as a director of Tethys Petroleum – an oil and gas exploration and production company in Asia.

The inquiry was launched after Mr Lilley spoke in the House of Commons last year about renewable energy, when he defended energy companies and their rising prices.

The MP is on the Commons energy and climate change committee.

The Conservative MP said the Commissioner for Standards has said there was no conflict of interest.

But, he had been advised that, as he is a director of Tethys Petroleum, and “in case anyone jumped to the conclusion” that the company had interests in the UK, “I might have been advised to explain to the House of Commons that its interests are exclusively in central Asia and therefore were irrelevant to [debate].”

Mr Lilley’s seat will be contested by Rachel Burgin for Labour in next year’s General Election.

Mrs Burgin said: “It is important that MPs declare their financial interests both in the Register of Members’ Interests and also before any relevant debate in Parliament.

“This is so that it is clear that MPs are acting in their constituents’ interests rather than for their own financial benefit.

“Mr Lilley has declared his very extensive financial interests in the Register of Members’ Interests and I trust he will fully co-operate with the inquiry into whether his interests in an oil and gas exploration company based in central Asia ought to have been declared in a debate on UK energy policy.

“There is a strong case to be made that for the sake of the UK’s energy security, we should import less fossil fuels and, to that end, we should be building our own energy facilities in this country. There is also a case to be made that in the interests of tackling climate change, more of those facilities should be built using renewable technology.

“If, on the other hand, the workings of an oil and gas exploration company based in Central Asia is not relevant to UK energy policy, it begs the question as to why Mr Lilley is wasting his time on it when his time could be better spent serving the people of Hitchin and Harpenden. If I was the MP, I wouldn’t take a second job at all.”