Medlyn told the Telegraph that it was her belief NRL players used group sex sessions as a form of team bonding.
The newspaper said Thompson - who joined the Warriors at the start of the 2015 season - had arranged for Medlyn to come to his hotel room the night before the Warriors' last game of the 2015 season, even though he shared the room with a teammate, who was not involved in the activity.
The Warriors lost narrowly to the Bulldogs the following day - they had led with less than three minutes to play before a late James Graham try - for their eighth successive defeat. In that game Thompson registered 12 runs for 100 metres, with 19 tackles. He made two errors and had two missed tackles.
The Warriors were made aware of the 2015 incident earlier this year, and Thompson was disciplined at the time for breaching team protocol.
The NRL Intergrity Unit were also notified about the matter but it's understood the unit is not actively investigating it.
The Warriors are satisfied there are no other issues to be addressed, as there is no suggestion that the activity between Medlyn and Thompson was anything other than consensual and Thompson is currently up to date with his child support payments, which Warriors chief executive Cameron George said had been confirmed by Thompson's lawyer and verified by documentation from the Department of Human Services in Australia.
George added it was a personal matter which was being handled by Thompson, his ex-partner and their respective lawyers.
But the episode does raise questions over whether Thompson fits the culture the club is trying to build.
The 29-year-old was also involved with the sleeping pills and energy drinks incident after the round eight loss to the Storm last year, which was a black mark against his name.
It resulted in six players (Ben Matulino, Manu Vatuvei, Sam Lisone, Albert Vete and Konrad Hurrell were the others) being stood down from the following game.
Thompson has been a decent performer at the Warriors since he arrived in 2015, though his output over the last two seasons hasn't matched his impressive debut year.
He averaged 7.7 carries and 54 running metres this year, a decrease from 9.9 and 85 respectively last year. His defensive statistics were also down.
It was always possible that Thompson would get squeezed out of the roster in 2018 and beyond, especially after the signings of back rowers Tohu Harris (Storm) and Leivaha Pulu (Titans), but the off field incidents haven't helped his cause.
The club offered Thompson a new contract early this season, which the former Kiwis squad member chose not to take up, and there is no current offer on the table.