Former Welsh secretary Stephen Crabb is being investigated by the Conservative Party after newspaper claims he sent suggestive text messages to a woman.
The Preseli Pembrokeshire MP allegedly made comments to a 19-year-old who applied for a job in his office in 2013.
He has been referred to a disciplinary panel set up under a new Tory code of conduct.
BBC Wales contacted Mr Crabb who declined to comment.
The allegations published in the Telegraph and other newspapers last weekend are said to have taken place during his time as a Wales office minister.
In the article, Mr Crabb admitted sending the messages and saying "some pretty outrageous things" to the woman after interviewing her for a job, adding that the messages "basically amount to unfaithfulness".
It is the second allegation of its kind made against Mr Crabb, who resigned from his cabinet role as work and pensions secretary in 2016 following similar allegations said to have happened during the EU referendum campaign.
The married MP, who was Welsh secretary between 2014 and 2016, was one of several contenders for the Tory leadership who lost out to Theresa May.
The Conservatives published a new code of conduct for their MPs and other elected representatives on Friday in the wake of sexual harassment allegations.