Colm Murphy also told investigating detectives he had never been in the Co Tyrone market town devastated by the August 1998 Real IRA attack.
Transcripts of his interviews with gardaí, carried out months after the blast, disclosed how he could not explain his mobile phone being traced to Omagh that day.
Murphy, a Dundalk-based contractor and publican, is being sued along with former employee Seamus Daly, from Culaville, Co Monaghan, over the bombing which killed 29 people and injured hundreds more.
Both men deny the claim against them.
They were ordered to face a civil retrial after their appeals against being held liable for the bombing were upheld.
Two other men found responsible in the initial landmark ruling in 2009, convicted Real IRA leader Michael McKevitt and fellow dissident republican Liam Campbell, failed to have the findings against them overturned.
Lawyers for some of the victims' relatives, who have brought the action, allege that Murphy and Daly played central roles in the terrorist operation.
They claim that Murphy supplied mobile phones to the bomb team, and that evidence links Daly to a call made shortly after the 15 August blast.
During day two of a trial expected to last six weeks, Brett Lockhart QC, for the plaintiffs, read out transcripts of Murphy's gardaí interviews in February 1999.
In the questioning sessions, he claimed to have taken his son quad biking in the mountains near his home on the day of the bombing.
Later that day, he said he went to the pub he owned in Dundalk, the Emerald Bar, staying until closing time.
At one stage he told detectives: "I was never in Omagh in my life. I had no hand, act or part in the Omagh bombing."
Murphy said he only become aware of what had happened when he saw a television newsflash.
Asked to explain how his mobile phone was tracked moving from Co Monaghan into Omagh, he said he didn't know.
The court also heard details of the scale of the police examination of mobile phone traffic.
A former RUC analyst, who studied data on both sides of the border, told how she looked at times of calls and mast locations in an attempt to identify numbers of interest to the investigation team.
"Altogether there was something like five million records of cell-site analysis," she said.
The trial continues.