The Garda Commissioner is expected to reveal she believes the falsification of garda figures goes beyond traffic data.

Noirin O Sullivan will tell the Oireachtas Justice Committee this morning she believes false figures may extend into further areas of policing.

Noirín O'Sullivan's been called before the Oireachtas committee after revelations of a fake one million breath tests and 14,700 cases of wrong court convictions for speeding.

Her opening statement for this morning's hearing was leaked yesterday and in it she says she has a real fear that the falsification of figures goes beyond traffic data.

That will be one element she'll face a grilling on this morning, as well as why Gardaí have been beset by scandals under her leadership.

Fianna Fáil will be watching her performance closely as the party is at the moment unable to express confidence in her.

Commissioner O'Sullivan will also be asked about the financial scandal at the training college and will have to address claims that she's been holed up with former commissioner Martin Callinan preparing for the disclosures tribunal.