DUBAI - Iran's ambassador to Britain said the Iranian tanker caught in a stand-off between Tehran and the West is expected to leave the British territory of Gibraltar on Sunday night.

"With the arrival of two specialised engineering teams to Gibraltar ... the vessel is expected to leave tonight," Hamid Baeidinejad said on Twitter.

British Royal Marines seized the vessel in Gibraltar in July on suspicion that it was carrying oil to Syria, a close ally of Iran, in violation of European Union sanctions.

(Writing by Lisa Barrington; Editing by David Goodman) ((lisa.barrington@thomsonreuters.com;))