MT Desh Shanti, belonging to the Shipping Corporation of India (SCI), was detained by the Iranian Revolutionary Guards Corps (IRGC) in the Persian Gulf Aug 13.
"India has been in touch constantly with Tehran over the matter, but there has been no progress regarding release of the ship," the external affairs ministry spokesperson said.
Iran has demanded an anti-pollution undertaking from the ship's captain and SCI for releasing the vessel. Tehran has termed the detention as a "technical and non-political issue".
The vessel was carrying 140,000 tonnes of Basrah crude oil from Iraq to India.
According to Iranian media reports, the oil tanker had been impounded because it discharged its oily ballast water 30 miles away from Iran's Lavan Island in the Persian Gulf, causing a 10 mile long oil slick in the sea.
India has cut its crude imports from sanctions-hit Iran.
--IANS (Posted on 21-08-2013)