He announced he had left last week.
The 43 year old, best known for his role as Will Schuster on the hit musical comedy, was a judge on So You Think You Can Dance where amateur dancers took to the stage in hopes of winning a grand prize.
Confirming he left the show last week only days before the season 17 premiere, it is now being reported that it was due to inappropriate behaviour on set.
He said in a statement to PEOPLE at the time: “Having the opportunity to be a judge on So You Think You Can Dance was an incredible honour for me. Therefore, it is my deepest regret to inform you that I will be leaving the show.
“After filming the audition rounds for the show and completing the selection of the 12 finalists, I did not follow competition production protocols, preventing me from being able to judge the competition fairly.
“I cannot apologize enough to all involved and I will be watching alongside you all on what I know will be one of the best seasons yet.”
A source has since revealed to PEOPLE that he was fired due to the texts, with the insider saying he “had an inappropriate relationship with a female contestant”.
They said: “They didn’t have sex, but he reached out to her through flirty direct messages on social media.
“She felt uncomfortable with his line of comments and went to producers, who then got Fox involved. He was fired after they did their own investigation.”
While they never met up off-set, the insider said that the messages “crossed a line” and it is believed Matthew will appear in upcoming pre-recorded episodes.
His replacement is set to step in during the next stage of filming.