Line of Duty star Vicky McClure has revealed her son on the hit show will be played by her real-life nephew.
The actress will reprise her role of DI Kate Fleming when the show returns for its fifth season tonight on BBC One, which will explore a bit more of her home life.
McClure said: "She's feeling pretty good, she's got a promotion so she's got a little bit further in her career and taking on more responsibility.
"She's back with her fella and the home is a happy place. She's got a bit more time with her son as her promotion gives her that flexibility, so we see her in a good place."
She added: "My son is played by nephew Kai. When it was written originally I had a daughter, and I said to Jed (Mercurio, the creator) it would be great if I could have a son instead because I could use my nephew.
"It will always be his role now and he really enjoys it - he did really well this year, he did some improvising, I'm very proud of him."
McClure said she has also been delighted by the addition of a female director to the Line Of Duty crew for the first time in the show's history.
She said: "It's been amazing, I absolutely love what Sue Tully is doing. I think she's bringing a different energy to it. John Strickland has obviously been with us some years so he's an old hand at it.
"I'm really glad we've got a female director on board and I wish we had more but Sue's a great representation of being able to come in and know what she wants and gets it shot the way she wants.
"She is doing some really interesting things with the camera.
"Plus she's an actor's director - being that she was an actor so she really understands what it is we need and that's been great."
Line Of Duty is on BBC One at 9pm.
