Letters announcing the bonus for Italian newborns were addressed to more than 600,000 babies in January, signed Big Kiss, Silvio Berlusconi".

Some 3,000 immigrant families made successful claims as a result.

Some Italians dismissed the bonus as an election gimmick by the prime minister, who later narrowly lost at the polls.

The finance ministry has stepped up its efforts to reclaim money paid to families who are not Italian or other European Union citizens resident in Italy.

It has issued bank details for the money to be repaid, Reuters news agency reports.

Italy has one of the lowest birth rates in the world, and the bonus was presented as an incentive to have more children. It was offered to parents of babies born in 2005 and came with a letter addressed to the infant:

Best wishes for your arrival, do you know that the budget has put aside 1,000 for you? Big Kiss, Silvio Berlusconi."