Half of the personal injury claim cases that one of Ireland's largest motor insurers brings to court are "potentially fraudulent".
Allianz said it challenged more than 1,500 claimants in the courts last year.
The revelation came as a string of insurers criticised the slow pace of insurance reform, on the second anniversary of the publication of the Government's first cost of insurance working group report.
Allianz Ireland said each case it had won had delivered average savings of €20,000.
The insurer currently has 500 cases awaiting trial.
Chief executive of Allianz Ireland Sean McGrath said the court victories against fraudsters were good news for the industry and for the consumer, who bore some of the cost of fraudulent claims.
"Nearly half of all claimants' cases that Allianz contests in court are potentially fraudulent," he said.
He said the cost of challenging fraudulent claims was not cheap, but the long-term benefits outweighed the initial cost.
Insurance Ireland demanded that the cost of insurance working group must complete its work this year. The representative body for the industry said soft-tissue whiplash claims were almost five times higher here than in Britain.
Insurer Liberty called for the implementation of more judicial and policing reforms.
It wants the immediate establishment of a Garda Insurance Fraud Unit, dedicated to tackling insurance fraud, funded by the insurance industry, but independent of it.
Liberty said there should be an amendment to existing law to require applicants to swear a verifying affidavit that their claims were valid.
Just how long will it take before those in authority in this country realise that ordinary, honest citizens have lost patience with the whiplash epidemic? There are few things more infuriating than knowing that many of the claims are a try-on, yet the claimsters get money anyway.