Turkey has intercepted a vessel in the Mediterranean suspected of carrying weapons and ammunition to Syria, a diplomatic source told AFP on Wednesday.

"We received information that the vessel has a cargo of arms and ammunition headed for Syria," the source said on condition of anonymity, adding that Turkish authorities would search the vessel.

The Antigua and Barbuda flagged Atlantic Cruiser which anchored off the coast of Iskenderun port Wednesday morning belongs to a German company.

The search of its cargo was delayed until Thursday morning due to stormy weather, the Anatolia news agency reported.

The German shipping firm denied allegations Monday that its vessel was carrying Iranian arms to Syria, violating EU sanctions against the Damascus regime.

German news weekly Der Spiegel reported at the weekend that the Atlantic Cruiser, owned by German company Bockstiegel but chartered by a Ukrainian firm, had been stopped on the high seas with Iranian weapons on board.

Bockstiegel said they had no indication that the cargo included arms or ammunition as stated in the press, and the Ukrainian company that chartered the ship also said that the cargo contained no weapons, but legal goods for civilian use.

Bockstiegel acknowledged that the ship's crew had only been able to check "the container stacked at the top", and the ship would continue its journey only after it passes the inspection.

Late Wednesday Bockstiegel said in a statement that the Atlantic Cruiser entered the port of Iskenderun "unsolicited and as agreed" with German and Turkish authorities.

The ship was "never stopped or intercepted by Turkish authorities", the company said, adding that a stop in Iskenderun had been planned from the start.

Iran is under a UN arms embargo imposed in 2007 due to its alleged nuclear activities while Western countries have declared a similar embargo against Iranian ally Syria since a bloody crackdown on dissent began over a year ago.

Amid Damascus' violent crackdown, Turkey imposed gradual sanctions against its neighbour -- including interception of arms shipments there by air, land and sea.

Throughout last year, Turkey intercepted several ships and trucks suspected of carrying weapons into Syria through Turkish territory.