Opposing news reports fueled confusion Tuesday over the fate of an oil tanker seized near the British territory of Gibraltar last month.

Jalil Eslami, deputy head of Iran's maritime agency, said Tuesday that the tanker, Grace 1, would soon be released by Gibraltar authorities.

"We believe that (the) Grace 1 oil tanker will resume operation under (the) Iranian flag in international waters in the very near future," Eslami said, according to Iran's Fars news agency.

Fars, quoting unidentified Gibraltar authorities, said the tanker would be freed by late Tuesday.

But Western media reports said a senior official in Gibraltar called the report "untrue."

Although Grace 1 was seized by British forces, Britain said on Tuesday that investigations into the tanker were a matter for Gibraltar. The Gibraltar Supreme Court is scheduled to hold a hearing on the case on Thursday.

Britain has accused the vessel of violating European sanctions by taking oil to Syria, a charge Tehran denies.

In retaliation, Iran seized the British-flagged Stena Impero tanker in the Strait of Hormuz on July 19 for alleged maritime violations.

Tensions in the Persian Gulf have been rising since the United States pulled out of the international 2015 nuclear treaty, under which Iran agreed to curb its nuclear work in return for lifting most international sanctions on Tehran.

Britain and other European parties to the nuclear deal have been trying to salvage it by shielding Iran's economy from reimposed tougher U.S. sanctions.