The talks came amid Turkish objections to Danish Prime Minister's Anders Fogh Rasmussen possible nomination for NATO secretary-general, in which the long-standing spat over Roj TV figures prominently.

A prosecutor for the Copenhagen police and two state prosecutors "were in Ankara on Thursday and Friday as part a probe into Roj TV," Danish Ambassador Jesper Vahr told AFP.

"We are working closely the Turkish authorities in the investigation," he said, adding the prosecutors met with justice and foreign ministry officials.

Turkey has long urged Denmark to ban Roj TV, arguing that the channel is the mouthpiece of the Kurdistan Workers' Party (PKK), which has fought a bloody 24-year separatist campaign in Turkey's southeast and is listed as a terrorist group by much of the international community.

Vahr denied the probe was aimed to soften Turkey's objections to Rasmussen's NATO bid, stressing that Denmark "condemns" the PKK and was "instrumental" in including the group on the EU list of terrorist organisations.

Turkish Prime Minister Recep Tayyip Erdogan said Friday that Rasmussen would be unwelcome as NATO secretary-general, stressing that Ankara was "seriously disturbed" over Copenhagen's failure to act against Roj TV.

In another objection, he cited Muslim anger over Danish cartoons of the Prophet Mohammed in 2005 and said leaders of Islamic countries were pressing Turkey, NATO's only predominantly Muslim member, to veto Rasmussen.

The Danish premier is a favourite to succeed NATO Secretary General Jaap de Hoop Scheffer in August, with most of the alliance's big powers solidly behind him, but Turkey seen as a key obstacle.

NATO leaders meet on April 3-4 for a 60th anniversary summit, but it is unclear whether they will announce the next secretary general of the 26-nation alliance.