Social welfare amnesties have resulted in a sharp drop in the number of people prosecuted for fraud, according to the annual report of the Comptroller and Auditor General for 1996.
The report says that £18.9 million in overpayments were recorded by the Department in 1996, of which £13.6 million was attributable to fraud or suspected fraud.
Only 56 people were prosecuted last year although there were 10,500 cases of fraud.
Just over 200 people a year were prosecuted in the six years from the beginning of 1985 to the end of 1990.
But social welfare amnesties in 1991 and 1993 slashed the number of prosecutions to an average of just over 40 a year for the next six years.
The figures in yesterday's report show that the Department has developed a remarkable record of successful prosecutions. Every prosecution in the past four years has resulted in a conviction.
The average fraudulent overpayment detected last year amounted to £1,300.
The social welfare payments most commonly claimed fraudulently are unemployment assistance and unemployment benefit. Means-tested old age pensions accounted for a substantial proportion of the money fraudulently claimed.
Every year, the Department writes off large sums of money, paid through fraud or error.
Last year, it wrote off £7 million and the previous year £10 million.
But it recovered nearly £8 million last year, more than half in cash repayments from recipients and the rest by withholding money from welfare payments.
In recent years, the Department has been able to recover only half the money owed to it.
But in July of last year, it adopted a new code of practice which requires it to take account of the interests of taxpayers and social insurance contributors. The code includes a stipulation that every effort be made to recover overpayments in full but says that in certain circumstances the debt may be cancelled, reduced, deferred or suspended.
The report refers to a number of moves by the Department in recent years to detect fraud:
An unspecified number of married people claiming the Lone Parent's Allowance was detected when the Department got a computer tape of marriage records from the General Registrar's Office.
Its "Estate Case Recovery Unit" is currently investigating 143 cases in which deceased pensioners are thought to have failed to declare their full means when they were alive.
A computer tape obtained from the UK Department of Social Security enabled the Department to identify nearly 400 pensioners who had not disclosed their British pensions when applying for an Irish pension.