Dame Nuala O'Loan gave evident to the committee
The former Police Ombudsman has said the findings of a government inquiry that examined intercept intelligence surrounding the Omagh bomb were "odd".
The inquiry concluded the 1998 Real IRA bombing could not have been prevented and that intelligence was not withheld.
Dame Nuala O'Loan told the Northern Ireland Affairs Committee it may "never be known" if the bombing could have been prevented.
She said she was "confused" by some of the report's findings.
The 1998 explosion killed 29 people and unborn twins
Dame Nuala confirmed to MPs that there were telephone numbers and names which Special Branch could have given to CID Officers investigating the bombing.
The inquiry into how intelligence was handled was chaired by Sir Peter Gibson, with a remit to investigate how intercept intelligience was shared in the Omagh bomb investigation. It was set up after a BBC Panorama Programme claimed security officials were listening to the Omagh bombers.
A total of 29 people and two unborn babies died in the August 1998 blast in the County Tyrone town.
As well as Dame Nuala, the committee head from Jason McCue, a lawyer who represented some of the bereaved families.
He said that it should be examined in more depth.
"It strikes me that Gibson, first of all, is not a policeman so how he can derive what would have been of use to the investigators is beyond me," he said.