The Data Protection Commissioner has found that Minister for Justice Alan Shatter broke the law by disclosing personal information about Independent TD Mick Wallace.
Mr Shatter revealed on RTÉ's Prime Time last May that Mr Wallace had been cautioned by gardaí for using his mobile phone while driving.
The minister later told the Dáil that he was given the information about the incident, which occurred in Dublin in May 2012, by then garda commissioner Martin Callinan.
Data Protection Commissioner Billy Hawkes ruled today that Mr Callinan was not in breach of the Data Protection Acts when he passed the information to the Minister for Justice.
He said it was the garda commissioner's duty to keep the minister fully informed.
While the minister has been found to have breached the Data Protection Acts, he has not committed an offence and is not subject to any penalty under the acts.
Mr Hawkes said it is a matter for any individual who feels they may have suffered damage to seek legal advice.
Minister Shatter said this evening he is examining the report with a view to taking any appropriate further legal steps.
His spokesperson said the minister is considering appealing the decision to the Circuit Court, which he has 21 days to do so.
Mr Shatter said he acknowledged the importance of the role played by the Data Protection Commissioner.
However, he also said the matter was also considered by the Standards in Public Office Commission, which rejected a complaint by Mr Wallace.
Mr Shatter described his remarks on Prime Time as a mistake that he would not make again in similar circumstances.
Mr Wallace has said Mr Shatter should resign, saying he was unfit for office.
He said Mr Shatter interprets the law as he chooses.
Mr Wallace said while Taoiseach Enda Kenny continues to stand by the minister, the people of Ireland have long lost confidence in him.
When asked if he would take legal action, he said he will be liaising with his legal advisers.