Berlin, May 9: A German man is exploiting a loophole in the law to become the legal father of 1,000 foreign children so they can claim German passports.

J?rgen Hass, who lives in Paraguay, says it is a personal “act of revenge” against the state.

He has so far adopted 300 children from seven countries and plans to adopt a further 700 by the end of the year. The children he has adopted so far come from Paraguay, Romania, Hungary, Moldova, Russia, Ukraine and India.

Under a law on children’s rights dating from 1998, a man can become the legal father of a child as long as the mother gives her permission and there is no record of a birth father.

Once adopted, the child can gain a German passport and have access to the welfare state as well as education.

Hass, a former insurance salesman who lives in Paraguay on a ?700-a-month pension, said he wanted to help the impoverished children to lead better lives, but that his main motivation was to exact revenge on the state.

Hass, a former local politician for the Free Democratic party, was sentenced to three years in prison in 1987 for fraud. The 56-year-old claims he was wrongly imprisoned and “treated worse than a dog” while in jail. He still professes his innocence.

He described the adoption campaign as his “personal, private revenge”.

“A family of eight in Paraguay can live off a single German child’s allowance very happily,” he said.

It is not clear how many of them are living in Germany.

Authorities say they cannot act until the law is changed. They are aware of dozens of other cases in which German men are exploiting the loophole, including a Berliner who every year declares himself the legal father of around 10 children of single mothers from Bosnia and Vietnam.

He is alleged to receive ?1,026 from middlemen for each child he adopts.

Once the children become German citizens their mothers have the chance to secure a residency permit and to claim social welfare payments for themselves and their children. The man is said to have so far cost the state about ?345,000.