Brother and sister fight for right to continue their incestuous affair

Patrick Stübing was adopted and did not meet his biological family for the first time until he was 18. It was a fateful encounter, leading to his life being torn apart by sexual love for his sister and more than two years in jail for committing incest.

Mr Stübing, 29, and his sister Susan, 24, who have four children together, announced plans yesterday to take their case to Germany's constitutional court in an attempt to overturn the century-old law that incest is a crime.

"We want the law which makes incest a crime to be abolished," said Mr Stübing - who faces the prospect of another jail term for continuing his relationship with his sister. "We do not feel guilty about what has happened between us," both added in a joint statement.

The couple's case has sparked wide controversy. Many of Germany's European neighbours, such as Belgium, Holland, and France, do not treat incest as a criminal offence.

Several German doctors have implied that the ruling is necessary to prevent illnesses caused by inbreeding. However, a growing number of politicians and legal experts have called for the law - which formed part of the "racial hygiene" policies of the Nazi era - to be scrapped.

"We are dealing with a piece of legislation which dates back to the last century and which no longer makes any sense," said Jerzy Montag, a spokesman for Germany's Green party.

The case of Mr Stübing and his sister defies popular notions about incest because the couple did not know each other during childhood. Adopted at the age of four in Communist East Germany, Patrick was only allowed to go in search of his real family when he reached 18.

His father had died in the interim, but he found his mother, Annemarie, and Susan in the east German city of Leipzig in 2000. Six months after the reunion, Annemarie died of a heart attack. Mr and Ms Stübing were the sole remaining members of a once-divided family. Drawn together in grief, they fell in love. "There was nothing we could do about it," Ms Stübing said.

They went on to have four children. All but one of them have been placed in care and two are mentally damaged as a result of inbreeding. In 2002, Mr Stübing was given a one-year suspended sentence after being found guilty on 16 counts of "illegal coitus" with his sister.

The authorities placed their first son, Eric, in the care of a foster family. Two other children followed in 2003 and 2004. Mr Stübing was subsequently jailed for 10 months for failing to respect the terms of his suspended sentence. Before starting his jail term, the couple conceived their fourth child, Sofia, who was born in 2005.

Mr Stübing and his sister found themselves before the courts again in November 2005 for having their younger children and Mr Stübing was sentenced to two and half years in jail for recommitting incest. His sister was placed under the care of a social services department.

Mr Stübing, an unemployed mechanic, was released from jail last year and is still living with his sister. Although he has had himself sterilised to avoid fathering more children, he could be sent back to jail at any time for persistently reoffending.

The couple insisted in an interview that they would not have had additional children if their son had not been taken away from them by the authorities. They said that all they wanted to do was to "live together as a family".

Endrik Wilhelm, the couple's lawyer, who will take their case to the constitutional court, said he believed they had a good chance of winning. He pointed out that no law forbids older people or those with hereditary diseases from having children even though, as in the case of incest, their children could suffer problems with mental development.

"This is a case about family rights and the right to sexual self-determination," Mr Wilhelm said. "Patrick and Susan are not doing anyone any harm."