MNA � Head of Iran�s Foreign Policy Strategic Council Kamal Kharrazi said that the oil tanker case should be decided according to the due process in Iran, noting London�s threat to impose sanctions on Tehran will not be effective.

UK�s threat to impose sanctions on Iran will not yield any result, he told IRNA on Saturday, framing, �What sanctions London could impose that is not in place [now]?�

�We hope that the English would free the Iranian oil tanker and that legal proceedings in Iran would lead to the release of the English tanker,� he added.

He went on to say that during the past 250 years, Iran has never attacked any country but, as proved, it is serious in defending its territorial integrity.

Upon the request of Iran�s Ports and Maritime Organization, IRGC seized British-flagged Stena Impero on Friday in the Strait of Hormuz since the vessel had switched off its transponder and moving in the wrong direction, increasing the risk of collision with other ships.

The Sunday Telegraph reported that Foreign Secretary Jeremy Hunt would announce some diplomatic and economic measures on Monday in response to the detention of the Stena Impero.

"Unlike the piracy in the Strait of Gibraltar, our action in the Persian Gulf is to uphold international maritime rules," Iranian Foreign Minister Zarif tweeted on Saturday.

British Royal Marines in Gibraltar stormed the Iran-operated 300,000-tonne Grace 1 and detained it on July 4, accusing it of carrying oil to Syria in possible violation of the European Union�s sanctions on the Arab country. Iran condemned the move as �piracy� and summoned Britain�s ambassador in protest over it, highlighting that neither the tanker was headed to Syria, nor Iran is a member an EU member and subject to any European oil embargo.