A German comic has been placed under police protection after he insulted the Turkish president Tayyip Erdogan with a crude poem prompting the government in Ankara to seek the funny-man's arrest.

Jan Boehermann read a poem on ZDF on March 31 which linked the hard-line Turkish president with bestiality and the suppression of Kurdish and Christian minorities, prompting an international row.

Turkish officials contacted Angela Merkel's government demanding action against Boehmermann, demanding they prosecute the comedian for insulting a head of state.

German comedian Jan Bohermann, pictured, has insulted the Turkish president Tayyip Erdogan

President Erdogan, pictured, has demanded Bohermann is prosecuted over the insulting poem

The incident has caused an international row which must be handled by Chancellor Angela Merkel, pictured

Erdogan also launched a legal action against Boehermann over his controversial poem.

Mopo.de is reporting that German police have been forced to offer Bohermann protection followoing his outburst.

Chancellor Merkel has faced criticism at home over her willingness to deal with Erdogan over the current EU migrant crisis.

Erdogan is known for his intolerance of criticism and readiness to take legal action. Turkish prosecutors have opened nearly 2,000 cases against people for insulting him since he became president in 2014, the justice minister said last month.

Merkel's spokesman Steffen Seibert said: 'The assessment of the Turkish cable and of further action resulting from it is still going on. We ask for patience.'

Seibert also reiterated Merkel's commitment to freedom of speech, but tried to separate that from the immediate political reality.

He said: 'It is important that the migrant deal with Turkey is implemented. We, Germany, and Turkey have a mutual interest in this succeeding ... but totally separate from that, we clearly acknowledge Article 5 of our constitution, which guarantees freedom of opinion, of science and of art.'

Critics argue that Merkel partly brought the problem on herself, by telling Turkish Prime Minister Ahmet Davutoglu on a phone call that the poem was deliberately offensive.

It would be legally possible under German law to prosecute Boehmermann. But as practical matter, such prosecutions are very rare. Only a handful of investigations have been conducted under the relevant laws over the past 15 years, say officials.

Under the relevant section of Germany's criminal codes, the government has to authorise prosecutors to pursue a case against Boehmermann. Requiring such political intervention in a judicial matter is antiquated and should be abolished, critics say.

A spokeswoman for the Justice Ministry said there were no immediate plans to abolish it but that the ministry was aware of a discussion taking place within some political parties.

Meanwhile, Turkey has invited Merkel to inspect a new refugee facility for dealing with Syrian refugees, although it is understood she will not be attending the meeting.

Seibert said there would be no trip on April 16.

However, Davutoglu had said that Merkel would join other European leaders in opening the school and hospital in the southeastern Turkish city of Kilis on the Syrian border, which houses a massive refugee camp for Syrians who have fled their country's devastating five-year war.

The centre was built under a new agreement between Turkey and the EU, spearheaded by Merkel, which aims to stem mass migration to Europe and the drowning of migrants trying to cross the Mediterranean in rickety boats.

Despite Davutoglu's announcement, German authorities never confirmed the visit to the city, which is frequently a target of rocket fire from Syria.