Independent deputy and police critic Clare Daly is under suspicion of driving under the influence of alcohol and faces a ban.
Socialist Daly was publicly critical of police last year when it emerged that some officers had nullified penalty points for celebrities and friends.
Daly has admitted she is now in trouble with the same police force and has said she should face the full rigours of the law if charged and found guilty of drink-driving.
The Irish Sun reports that the Dublin North deputy confessed she had taken whiskey before being pulled over by police in Dublin’s south inner city.
The paper understands that Daly gave a breathalyser sample at the scene.
The report says she was then taken to Kilmainham police station on suspicion of driving while over the limit.
It is understood that the outspoken politician then gave either a blood or urine sample.
The tests have been sent to the road safety bureau with results expected in a fortnight.
Daly told reports that she had taken a hot whiskey for a cold before making her way home.
In an interview with state broadcaster RTE, she said: “I was travelling in an area of south Dublin I’m unfamiliar with, I took an illegal turn and was pulled in by the police on foot of that.
“I had been with family and was given a hot whiskey for a cold.
“If that brought me over the limit, then that’s obviously a very serious mistake on my part and one which I take full responsibility for.”
Daly also said that she was surprised that details of the incident were leaked to the media without any charges having been brought or confirmation of her being over the limit.
She also insisted she should be treated to the full rigours of law like any other citizen if found guilty of drink-driving.
The former Socialist Party member added: “I am fully responsible for my actions and will take whatever consequences are necessary should anything come about.”