The M.T. Tour, a tanker identified by the United States as owned by a sanctions-evading company set up by Iran, passed through Egypt's Suez Canal on Tuesday.
The ship, owned by ISIM Tour Ltd, had been held up by Egyptian authorities for five days for not paying passage fees through the canal, which guarantees a right of passage to all ships during war and peacetime.
A canal official said the 81,000-ton M.T. Tour was carrying crude oil from Syria to Singapore, and had been "allowed to pass through the Suez Canal, after paying the required fees."
Reuters reported on Friday that the M.T. Tour was shipping a cargo of 120,000 tons of Syrian crude to a state-run Chinese company.
The official added that the tanker had come from Syria and was heading to Singapore. He said it had been carrying a Maltese flag but was now registered under a Bolivian flag. The official had no knowledge of any link with Iran.
Malta said on Sunday it was delisting the M.T. Tour on learning that it was carrying Syrian oil in breach of international sanctions.
Western and Arab countries have imposed sanctions on Syria in an effort to force President Bashar al-Assad to halt his crackdown on a civilian uprising that has slowly turned into an armed rebellion. The United Nations estimates that some 9,000 civilians have been killed.