The MV Alaed had its insurance withdrawn by The Standard Club in London while it was about 50 miles (80.4km) off Scotland’s north coast.
The insurer said it had sought more information on the boat’s cargo.
Withdrawal of insurance prevents the MV Alaed from sailing until its owner can secure new cover.
It was thought that the vessel had stopped off the Western Isles.
The Foreign and Commonwealth Office (FCO) said it was unclear where the vessel would now go.
The Russian embassy in London has not yet commented.
An attack in Syria is an attack against Iran, and now it seems, perhaps Russia.
I am not sure what should be done, considering that many more lives than just the Syrians are at stake, but some part of my suggests that we do something while the sane part of me says that anything we do is likely to cause a severe escalation of tensions in the region that will lead to major problems for allies and pseudo-allies in the Middle East, if not Europe.