A German flag flutters next to the dome of the Reichstag building. Germany's Ethics Council has called for sexual relations between siblings to be decriminalized. Reuters

Germany's Ethics Council has declared that sexual relationships between siblings should not be criminalized, in a statement Wednesday.

"Criminal law is not the appropriate means to preserve a social taboo. The fundamental right of adult siblings to sexual self-determination is to be weighed more heavily than the abstract idea of protection of the family," said the German Ethics Council in a statement.

The council's declaration follows the controversial case of a brother and sister who had four children together.

They had been raised separately and met when the brother, identified as Patrick S, was an adult and the sister, Susan K, was 16.

After authorities found out that they were living together as partners with their four children in Saxony, Patrick was sentenced to over three years for incest.

The couple has since been forced to live separately, and despite various attempts to appeal the guilty ruling at the European Court of Human Rights, there has been no success. Out of the four children, two are disabled.

Marriage between close relatives, and especially incest carries higher risk of children being born with genetic abnormalities.

The Ethics Committee based its conclusions on extensive research, which revealed that many incestuous couples are living apart secretly.

One of the cases that surfaced involved a woman who was in a relationship with her half-brother, and was being blackmailed by her father and ex-husband to end the relationship or lose her children.

Most European countries have laws banning incest, with the exception of France, where incest laws were abolished under Napoleon I.

According to an estimate by the Max Planck Institute, roughly 2 to 4 per cent of Germans have had "incestuous experiences".

A spokeswoman for Angela Merkel's ruling party Christian Democrats said the Ethic Council's recommendations are very unlikely to be implemented.

"The abolition of the offense of incest between siblings would be the wrong signal. Eliminating the threat of punishment against incestuous acts within families would run counter to the protection of undisturbed development for children," said Elisabeth Winkelmeier-Becker, legal policy spokeswoman for the party's group.