Iran's Revolutionary Guards seized a Togo-flagged oil tanker on Monday and arrested its 12 foreign crew members over alleged fuel smuggling, the Guards' news website said.
"The Revolutionary Guards' navy captured an oil tanker flying the Togolese flag and carrying over 1.5 million litres of smuggled oil," the Sepahnews website said.
"The vessel was brought to the port of Bushehr, along with its 12 crew members, who are of Indian and Sri Lankan nationality," it added.
Iranian naval forces frequently announce the detention of vessels transporting fuel in the Gulf.
In late January, Iran seized a vessel carrying two million litres of allegedly smuggled fuel, reports said. Fourteen crew members were arrested.
In May, Iran released seven crew members from a Portuguese-flagged container ship, seized on April 13, after accusing them of links to its arch-foe Israel.
Fuel prices in Iran are among the lowest globally, increasing the profitability of smuggling operations.