An oil tanker belonging to Iran's state-owned shipping line has been switching flags and using multiple companies to transport crude from Syria to Iran, illustrating how Tehran is helping to sidestep international efforts to choke the finances of Bashar al-Assad, Syrian president.
Documents obtained by the Financial Times show the vessel, operated by the Islamic Republic International Shipping Lines, sailed from Syria to the Gulf of Oman and then Iran, using different flags and changing owners.
Syria is reeling from the effect of sanctions introduced by the U.S., the E.U. and some Arab states over the past year. Analysts estimate the economy has contracted by between 2% and 10%, and the Syrian pound has declined in value by a third.
Oil sanctions imposed by the E.U., which bought 95% of Syria's oil exports, have hit the country particularly hard. The sector accounted for 20% of gross domestic product before the uprising began.
Iran and Syria have long been allies and Tehran, which faces a range of international sanctions over its nuclear programme, has been accused by the U.S. of assisting the Syrian regime in its crackdown against 14-month uprising.
Evidence of co-operation between the two countries comes as industry experts note a marked increase in the use of so-called 'flags of convenience' fluttering on Iranian-owned oil tankers.
International maritime laws require vessels to be flagged, showing the country to which they are registered. For a small fee, however, vessels can register with another country, such as Bolivia, Liberia and the Marshall Islands where analysts say registration standards are less stringent.
"The Iranian tanker fleet is becoming increasingly hard to track," said Hugh Griffiths, head of the countering illicit tracking unit at the Stockholm International Peace research institute. "As a result, Iranian-owned oil tankers are migrating to less regulated flags to continue doing business - whether it is shipping oil on behalf of the Assad regime in Syria, or transporting Iranian crude," Mr Griffiths added.
The recent voyage of the MT Tour, a tanker in part owned by IRISL --- which is itself subject to international sanctions --- offers a glimpse of how this works.
The Tour's movements were tracked by the FT through a combination of shipping records, company registries and sources monitoring the vessel.