A Scottish Conservative MP is being investigated by the Parliamentary Commissioner for Standards, The Herald can reveal.

David Duguid is being probed over allegations he failed to declare an interest in line with the Commons code of conduct.

According to the Commissioner’s page on Parliament’s website, the MP for Banff and Buchan may have breached the rule stating that “members must always be open and frank in declaring any relevant interest in any proceeding of the House or its Committees, and in any communications with Ministers, Members, public officials or public office holders.”

The investigation opened on November 27.

READ MORE: David Duguid says he followed 'prevailing rules' over wife's BP shares

There are no details over the exact allegations, but earlier this year there was criticism of Mr Duguid for not declaring his wife’s £50,000 of shares in energy giant BP.

 The former Scotland Office minister had long been a critic of introducing a windfall tax on oil and gas firms.

He was a minister in the UK Government from June 2020 until September 2021, before being appointed again by Liz Truss in October 2022.

His wife’s shares were not published in the list of ministers’ interests published by the Cabinet Office.

BP’s shareholder register shows Mr Duguid stopped being a shareholder in November 2012, on the same day his wife joined the company’s register of members.

At the time, the MP insisted he had "followed the prevailing rules for reporting relevant financial interests.”

A Scottish Conservative spokesperson said: “We are aware of the complaint and Mr Duguid is cooperating fully with the Standards Commissioner.”

READ MORE: Stephen Flynn's stunt with Labour mugs under investigation

Meanwhile, Stephen Flynn has been cleared of misusing official stationery.

The SNP Westminster leader was reported to House of Commons watchdog in July after a PR stunt which saw his team hand out mugs stuffed with official parliament compliments slips criticising Labour.

It came amid a row over Keir Starmer’s refusal to commit to repealing the two-child benefit cap.

The SNP handed out mugs in the Westminster press gallery which read: “Controls on family sizes. What’s the point of Labour?”

The matter was initially referred to the Parliamentary Commissioner for Standards who then passed it to the committee after Mr Flynn disputed the commissioner’s findings he had broken the rules.

The commissioner argued the slogan on the mug was an “eye-catching way to put across a party-political message”.

But Mr Flynn said that such an interpretation would “create a world where boring politics is good, but eye-catching and engaging politics to put forwards a message of importance to my constituents is not”.

The committee report said: “We do not believe that in Mr Flynn’s case issues of great moment are engaged, and we regret that it did not prove possible to conclude this matter at an earlier stage without the need for a formal referral to the committee.

“We take the opportunity to draw members’ attention to the requirement in the stationery rules that house-provided resources should not be used for party political campaigning, but do not consider it would be proportionate for us to take any further action in this particular case.”