An SNP MP has stood down from his role as chief whip of the party following sexual harassment allegations.

Patrick Grady was named by The Herald as the MP at the centre of the claims, with his party late on Tuesday night confirming an investigation is underway.

Letters obtained exclusively by Herald Westminster correspondent Hannah Rodger detail concerns about his behaviour at the SNP Christmas party on December 15, 2016, at London’s Phoenix Artist Club.

READ MORE: SNP 'protected' chief whip Patrick Grady over grope allegations

Prime Minister’s QuestionsThe SNP has confirmed an investigation into Mr Grady has commenced (Jessica Taylor/UK Parliament/PA)

The SNP MP was not fully investigated by the party despite multiple reports raising concerns about his behaviour.

An SNP spokesman confirmed Mr Grady, the MP for Glasgow North, had “stood aside” from his role as chief whip, adding: “The SNP has today received a formal complaint.

READ MORE: SNP under pressure to suspend two MPs at centre of harassment claims as new witness speaks out

“That now allows due process to take placed and we will not be commenting further while an investigation is under way.”