An operation was continuing to find the missing sailor, an emergency response official told Irna news agency.

Two rescue vessels and helicopters were dispatched after the Al Salmy 6 went down about 48km (30 miles) from the port of Assaluyeh on Thursday.

Winds were more than 70km/h (45mph) at the time, the Iranian official said.

The operations manager of the Dubai-based company that owns the Al Salmy 6, Salem Al Makrani Cargo company, told the Associated Press that the 138m-long (453ft) car transporter had been sailing towards the Iraqi port of Umm Qasr.

The bad weather initially caused the ship to list at a precarious angle, Capt Nizar Qaddoura said, but within hours it was fully submerged.

The crew comprised nationals of Sudan, India, Pakistan, Uganda, Tanzania and Ethiopia, he added.