Culture Secretary Jeremy Hunt is to be investigated over claims he failed to register donations from media firms.
Jeremy Hunt says he intends to amend the register of donations
Parliamentary standards commissioner John Lyon launched an inquiry after a complaint from a Labour MP.
It concerns meetings organised by private companies between July 2009 and March 2010, when Mr Hunt and his deputy Ed Vaizey were in opposition.
These were described as “networking events” where senior Conservatives met figures from the creative industries.
Labour has demanded the resignation of Mr Hunt over an “accumulation of evidence” that his relationship with Rupert Murdoch’s News International was too close at a time when he was overseeing the company’s attempt to take over broadcaster BSkyB.
But he has resisted the calls, saying he behaved with “integrity” throughout the process.
The investigation Mr Lyon is heading relates to separate allegations over Mr Hunt’s conduct while the Conservatives were in opposition.
It follows a complaint from the Labour MP Steve McCabe earlier this month.
Mr Vaizey stated in his entry in the register of interests that he and Mr Hunt had attended eight sponsored events between July 2009 and March 2010.
Mr Vaizey registered the events as donations worth £27,000. These are not cash donations, but estimates from Mr Vaizey of the cost to the companies concerned of hosting the events.
However, Mr Hunt did not declare the meetings against his name in the register. He has subsequently claimed that he attended only three of the eight meetings.
His spokeswoman said he had amended his register entry since the complaint was raised and the discrepancy had arisen because of “miscommunication”.
She declined to comment on the allegations, but added that Mr Hunt would co-operate with the commissioner’s inquiry.