Patrick Dempsey has been accused of "terrorising" the 'Grey's Anatomy' set

Former ex ecutive producer James D. Parriott told how things had grown so tense between the actor and creator Shonda Rhimes that she "needed an OG to come in as sort of a showrunner for 14 episodes” so he came in to orchestrate Patrick's exit.

He added: “There were HR issues. It wasn’t sexual in any way. He sort of was terrorising the set. Some cast members had all sorts of PTSD with him. He had this hold on the set where he knew he could stop production and scare people. The network and studio came down, and we had sessions with them.

“I think he was just done with the show. He didn’t like the inconvenience of coming in every day and working. He and Shonda were at each other’s throats.”

Another former ex ecutive producer, Jeannine Renshaw, also claimed there were tensions between the actor and his on-screen wife Ellen Pompeo,

who plays Dr. Meredith Grey, because the actress was "frustrated" by her co-star's attitude.

She said in an excerpt from the book shared by The Hollywood Reporter: “There were times where Ellen was frustrated with Patrick, and she would get angry that he wasn’t working as much.

“She was very big on having things be fair. She just didn’t like that Patrick would complain that ‘I’m here too late’ or ‘I’ve been here too long’ when she had twice as many scenes in the episode as he did.

“When I brought it up to Patrick, I would say, ‘Look around you. These people have been here since 6:30 am.’ He would go, ‘Oh, yeah.’ He would get it. It’s just that actors tend to see things from their own perspective… He’s so high energy and would go, ‘What’s happening next?’

"He literally goes out of his skin, sitting and waiting. He wants to be out driving his race car or doing something fun. He’s the kid in class who wants to go to recess.”

Jeannine recalled how Shonda decided it was the final straw when she "finally witnessed" Patrick's alleged complaining behaviour.

She said: "Shonda had to say to the network, 'If he doesn’t go, I go.' Nobody wanted him to leave, because he was the show. Him and Ellen. Patrick is a sweetheart. It messes you up, this business."

Patrick - who has daughter Talula, 19, and twins Sullivan and Darby, 14, with wife Jillian Fink - admitted he had found working on the show for so long "challenging" because he felt he never had control over his own life.

He said: "It’s 10 months, 15 hours a day. You never know your schedule, so your kid asks you, 'What are you doing on Monday?' And you go, 'I don’t know,' because I don’t know my schedule.

"Doing that for eleven years is challenging. But you have to be grateful, because you’re well compensated, so you can’t really complain because you don’t really have a right. You don’t have control over your schedule. So, you have to just be flexible."

The actor made a return to the programme earlier this year when his character appeared in a dream Meredith was having while in a coma battling coronavirus, with the pair finally getting married in a fantasy beachside wedding.