Chancellor Angela Merkel on Friday authorised a Turkish demand for a German TV comedian to be prosecuted over a crude satirical poem about President Recep Tayyip Erdogan in a bitter row over free speech.

"The government will give its authorisation in the case at hand," Merkel told reporters, adding that it was up to the courts to decide on his guilt or innocence.

However, Merkel also announced that Germany would by 2018 scrap the rarely enforced section 103 of the criminal code -- insulting organs or representatives of foreign states -- of which the comic, Jan Boehmermann, has been accused, as a result of the embarrassing affair.