Gibraltar’s leader attempted to deescalate the crisis with Iran over the fate of an oil tanker on Friday, saying it was “difficult to see” whether Tehran breached an agreement not to sell its oil to Syria.

Iran made assurances to a court in Gibraltar that it would not deliver the seized supertanker’s two million barrels of crude oil to the Syrian regime in order to secure its release.

After it was freed on Aug 18, the renamed Adrian Darya 1 sailed around the eastern Mediterranean for over a week before heading towards the Syrian coast and turning off its transponder on Sept 2. Iran claims it sold the oil to an unnamed private company.

Maritime trackers say it is likely the Adrian Darya 1's contents were off-loaded to Syria through smaller vessels. Britain and the US have said such a move is in violation of European Union and US sanctions and breaches the agreement.

Fabian Picardo, Gibraltar’s chief minister, however, said on Friday that “it is difficult to see whose word you’d take for it”.