The Competition and Consumer Protection Commission (CCPC) is at an “advanced stage” of an investigation launched three years ago into whether motor insurers and brokers had engaged in anti-competitive practices by openly signalling premium price moves.

“The CCPC’s work in the insurance sector is of high priority and we are working to conclude our investigation as efficiently as possible, however, we must also do so in accordance with the law,” a spokeswoman for the authority said, adding that the investigation is at an “advanced stage”.

“Our investigation must continue until we are satisfied that we are in a position to reach a conclusion on the conduct and so it is not possible to indicate when the investigation will conclude.”

The first comprehensive study of its kind has cast doubt on long-standing industry claims that higher car coverage costs are the result of spiralling payouts and increased claims.

Motor insurance premiums soared more than 70 per cent over three years before they peaked in 2016, according to Central Statistics Office data. Premiums have since come back by more than 25 per cent.

The CCPC initiated its inquiry in September 2016, around the time that motor coverage costs hit a high point.

Last May, the European Commission started a formal investigation into whether Insurance Ireland, an industry body, has been operating a cartel by restricting access to a claims database.

The database, Insurance Link, allows members of the organisation and large corporations that self-insure to access the claims history of individuals seeking to take out a new policy with a provider.

Insurance Ireland has said it is confident its practices are fully compliant with competition law.