An Iranian tanker captured by British Royal Marines in Gibraltar was not headed to Syria, Iran´s Deputy Foreign Minister Abbas Araqchi said on Sunday in a press conference broadcast live on state TV. Royal Marines seized the tanker on Thursday for trying to take oil to Syria in violation of EU sanctions. Araqchi said the giant tanker has a capacity of up to two million barrels of oil and that is why it was traveling through the Strait of Gibraltar rather than the Suez Canal. He did not give information on the tankers final destination. "Despite what the government of England is claiming, the target and destination of this tanker wasn´t Syria," Araqchi said. "The port that they have named in Syria essentially does not have the capacity for such a supertanker. The target was somewhere else. It was passing through international waters through the Strait of Gibraltar and there is no law that allows England to stop this tanker. In our view, the stopping of this ship was maritime robbery and we want this tanker to be freed." The 330-meter (1,000-feet) Grace 1, capable of carrying 2 million oil barrels, was halted in the early hours of Thursday by police and customs agencies in Gibraltar, a British overseas territory on Spains southern tip at the western entrance to the Mediterranean. The ship was detained four kilometers (2.5 miles) south of Gibraltar in what it considers British waters, although Spain, which lays claim to the territory, says they are Spanish. Araqhchi said the tanker was crossing the Strait of Gibraltar because its "high capacity" meant "it was not possible for it to pass through the Suez Canal". He insisted the tanker was intercepted in international waters and accused Britains Royal Navy of committing "maritime piracy". The tankers detention came at a sensitive time in Iran-EU ties as the bloc mulls how to respond to Tehran breaching the uranium enrichment limit it agreed to in the troubled 2015 nuclear deal. Iran is currently following "the legal path through court" but hopes the issue can be resolved by "ongoing diplomatic consultations", Araqhchi added. Iran Friday demanded that Britain immediately release the tanker, but Gibraltars Supreme Court ruled that the vessel can be held for 14 more days. An Iranian Revolutionary Guards commander threatened on Friday to seize a British ship in retaliation.