A House of Commons investigation has allegedly upheld a complaint against Patrick Grady, with the Glasgow North MP asked to respond to the finding.
However, the Daily Record reported claims against him were initially dealt with informally by the SNP, with Mr Grady allowed to stay on as chief whip – in charge of party discipline – and later fronting a Westminster debate on harassment.
Liberal Democrat Alistair Carmichael MP said: “It is the height of hypocrisy for the SNP to have conducted an informal investigation, covered up the result and then allowed the perpetrator to lead for the party on debates about the bullying of staff.”
Mr Grady quit as chief whip last year after claims of harassment were made public.
The MP was accused of inappropriately touching a 19-year-old SNP staffer in a London pub, as well as groping male researchers at a 2016 Christmas party.
Mr Grady reportedly took part in a behaviour-related training course in 2018 after the party tried to deal with the pub incident informally.
He took part in a Westminster debate in 2019 on the bullying and harassment of staff, during which he said: “Bullying, harassment, and a toxic culture of insecurity and under-mining have been found to be commonplace, and they are all perhaps manifestations of deeper-rooted cultures and behaviours associated with the abuse of power.”
Mr Grady also said: “Perhaps, on reflection, some of us will recognise our own behaviours."
An SNP spokesman said: “It would not be legally appropriate to comment while the independent parliamentary process is ongoing.”
Tory MSP Annie Wells said: “The brave complainer who came forward in this case will be in total despair as to how the SNP have handled it.
"It looks more like a cover-up with each revelation that emerges.
“From the outset, there has been a failure by the SNP to be transparent, whether to the complainer or the wider public.
“Urgent answers must be given by the SNP as to why they have kept crucial details of this case hidden for so long.”