Murder suspect Eamonn Lillis admitted he made up a story about a burglar killing his wife at their luxury home in north Dublin, his trial has heard.
The 52-year-old was also having an affair in the run-up to the brutal death of Celine Cawley, a top advertising executive and former model, prosecutors at the Criminal Courts of Justice said.
On the opening day of his trial, defence barrister Brendan Grehan said his client, who denies murdering his wife in December 2009, was making a number of admissions.
Among these, were that he lied to investigators about how Ms Cawley died on the decking at the rear of their home, Rowan Hill at Windgate Road, in the exclusive suburb of Howth.
The television producer will retract his original claims that a balaclava-clad intruder attacked his wife and then himself as he returned from walking the dogs on the morning of her death.
Prosecutor Mary Ellen Ring said forensic analysis of three mobile telephones used by the defendant revealed he was having an affair with a woman named Jean Tracey.
The woman is expected to give evidence that her lover admitted having an argument with his wife which turned violent.
Investigating gardai will also tell the trial they recovered a suitcase of blood-stained clothes in the attic of the defendant's house during follow-up searches.
Tissue and blood found embedded in the face of a watch worn by the accused also matched DNA samples of his late wife, Ms Cawley.
The couple, who have a teenage daughter, were well-known among advertising circles in Ireland through their company, Toytown Films, which makes commercials for television and cinema. Ms Cawley was also known for a minor role in the James Bond film A View to a Kill.