Sports presenter Richard Keys’ wife realised he was having an affair when she began writing a book about infidelity. Trained counsellor Julia Keys revealed she used her skills honed over a 20-year career to pen a book about the sensitive subject of helping women identify if their man is cheating.

Mr Keys, 59, is said to have continued his affair with 27-year-old lawyer Lucie Rose - a friend of their daughter Jemma - after previously pressuring his wife to into saying it never took place.

But it emerged last month that the pair spent two nights together in a West London hotel - prompting Mrs Keys to call her husband of 34 years a “pathological liar”.

In her first interview since claims of an affair re-emerged, published in the Mail on Sunday, she explained how her research in writing the book helped her discover how Mr Keys began showing classic warning signs of infidelity - signs she calls the “manscript”.

Mr Keys, for one, began being over protective with his mobile phone - and it paused her to stop and think: “Hang on. I think something is going on with Richard.”

Mrs Keys, 57, then explained how she acted on her suspicions and she said women should “trust” their gut feeling,