The Labour Party has now received a formal complaint about suspended MP Geraint Davies, Sky News understands.
Mr Davies was “administratively suspended” from the party pending an investigation into reports of “incredibly serious allegations of completely unacceptable behaviour”.
Mr Davies was first elected as an MP in 1997, but was out of parliament between 2005 and 2010. He now represents Swansea West.
Allegations regarding the 63-year-old politician came to light in a report by Politico published on Thursday.
He has not responded to any of Sky News’ requests for a statement, but regarding their claims, he told the website: “I don’t recognise the allegations suggested and do not know who has made them. None of them, as far as I know, has been lodged as complaints with the Labour Party or parliament.
“If I have inadvertently caused offence to anyone, then I am naturally sorry as it is important that we share an environment of mutual and equal respect for all.”
Sky News later revealed that Mr Davies had “boasted” about bringing sex workers into parliament for drinks, according to two of his colleagues.
Sky News has also seen evidence the Labour Party whips’ office was made aware of allegations many months ago, but did not take action.
Labour suspended the MP from the party and urged those who had been impacted by his behaviour to make a formal complaint so they could carry out an investigation.
Speaking to Sky News after the party suspended Mr Davies, one Labour MP said: “He would openly boast about bringing escorts and prostitutes onto the terrace and show them off.”
They said party officials had warned him to stop doing it, but no formal complaints had been made against him, adding: “They can’t take any action over hearsay.”
The claims were backed up by a Labour peer from the House of Lords, who saw him on the terrace with young women, and said there was always talk of him “favouring Eastern Europeans”.
The MP described Mr Davies as “a wrong ‘un” and “a sleazy man”, saying: “He would look you up and down, make lewd comments and touch you around the waist when he came up behind you.”
They said they and their colleagues were pleased the allegations had come to light, adding: “It is something he does to everyone. It is not unusual; it is just the pattern of his behaviour.
“He is one of the people that when people are new, they are told ‘don’t be alone with him, he’s a wrong ‘un’, and warned away from him.”
However, they said they had sympathy with party officials, who they claimed could not act without formal complaints being made.
Speaking to reporters on Thursday afternoon, Labour’s shadow Northern Ireland secretary Peter Kyle said he was “absolutely not aware” of any of the allegations against Mr Davies.
Mr Kyle said the party “takes this sort of allegation incredibly seriously” and that the alleged victims would be put “first and foremost” as an investigation is launched.
“The very day a formal complaint was made, Geraint Davies had the whip removed, he is no longer a Labour MP and a formal swift process will unfold,” he said.
Pressed on whether there could be any improvements to the complaints process, he said Labour has “constantly improved the process that unfolds with allegations like this”.
“Both the whips and the party have separate processes… they have independent processes in the right circumstances. We are constantly learning.”