The Turkish Ministry of Foreign Affairs denied Greek media reports that a Turkish Petroleum Company was carrying out oil exploratory works along the Greek continental shelf in the Mediterranean Sea, the state-run Anatolian Agency reported on Sunday.

Media reports earlier said a standoff ensued when a Greek gunboat was dispatched in the area, where a Norwegian ship was prospecting for oil in the southeastern Aegean escorted by Turkish frigate, Gediz, to impress "that this sort of research requires permission from Greek authorities," citing the Greek general staff.

The Malene Ostervold departed shortly after midnight after the Norwegian ambassador had been summoned by the Greek foreign ministry, but returned early on Saturday morning, the general staff was also quoted as saying.

The continental shelf (CS) dispute stems from the absence of a delimitation agreement effected between the two countries and it has a bearing on the overall equilibrium of rights and interests in the Aegean, as it concerns areas to be attributed to Turkey and Greece beyond the 6 mile territorial sea.

The continental shelf issue has in the past led to tensions between Turkey and Greece.