The Garda Commissioner says it's possible that gardai deliberately falsified the number of breath tests they carried out.

Noirin O'Sullivan has faced a grilling over how the force managed to exaggerate the number of tests they performed by almost 100 percent, or 1 million tests.

Commissioner O'Sullivan apologised for the grave mistakes of the last decade, and said it was a matter of collective failure.

Juliette Gash reports;

The Garda Commissioner's admitted they still don't know if the recording of a fake one million breath tests was deliberate or an error.

Noirín O'Sullivan's before the Oireachtas justice committee over the latest scandals to hit the force.

She's apologised for all the failures of the past ten years.

The Commissioner says they're still trying to investigate the current issues:

Asked about the logistics of the force and the audit into breath tests, the Garda Commissioner said that in 2014 she was almost single-handedly running the force of 14,000 people with five deputies.

She said this was not an excuse, but to give context.