The Accident Compensation Corporation recovered more than $1 million from fraudulent claimants last year.

The Minister for Accident Insurance, Lianne Dalziel, said in replies to written questions in Parliament that the corporation's fraud unit had investigated 789 people suspected of making fraudulent compensation claims, recovering $604,255.

In addition, the courts awarded ACC $531,014 in reparations from fraud prosecutions.

The figures come as concerns are raised about the possibility of an increase in fraudulent claims after the reintroduction of lump-sum compensation from April 1 this year.

Some believe that advantage will be taken of the scheme if claims of sexual abuse not proven in court qualify for lump-sum compensation.

Much of the workload of ACC's fraud unit in recent times has arisen from health professionals carrying out "phantom billing".

In the year to the end of last June, 39 health professionals were investigated by ACC's fraud unit.

A further 100 had "unusual" billing monitored.

The corporation deals with about $200,000 of fraud by phantom billing annually.

In the past year, one medical practice had to refund $59,000 to ACC after it was found to have billed the corporation for non-existent accident victims. The practice was closed and sold.

ACC also revealed that nearly 200 New Zealanders living overseas cost taxpayers an estimated $54 million in accident compensation in the past 12 years.

Fraud unit manager Robert Liberona said last year that since August 2000, the unit had identified 193 overseas claimants who had received an average $250,000 in compensation.

The average person received compensation for 12 years.

Once the costs of reports and rehabilitation were added, the average cost to the corporation for each patient was about $280,000 over 12 years.

Mr Liberona said a quarter of the 193 had not given ACC an overseas address.

Nearly 90 per cent of those traced were living in Australia, and 50 per cent of them were on the Gold Coast.

Mr Liberona said 50 per cent of the claimants were receiving compensation for soft-tissue injuries such as back and ankle strains.

Back injuries accounted for 40 per cent of the total.

The corporation normally expected such injuries to be resolved within 12 months.