A source close to the Gibraltarian government on Tuesday dismissed reports in Iran that the Grace 1 would be set free later in the day.
However, the British territory said last month a hearing on the tanker’s fate would take place on 15 August.
That followed a decision by the Supreme Court in Gibraltar to extend the period of detention for the tanker by a month, a deadline which expires on Saturday.
This time around the court could order a further extension, it could find that an offence was committed, or it could say the tanker is free to go.
The commandeering of the Grace 1 on 4 July exacerbated friction between Tehran and the West and led to the retaliatory seizure of a UK-flagged tanker in the Gulf a fortnight later.
Britain accused the Iranian vessel of violating European sanctions by taking oil to Syria, a charge Tehran denies.
The deputy head of Iran’s Ports and Maritime Organisation, Jalil Eslami, said on Tuesday that Britain was thinking of freeing the Grace 1 following an exchange of documents.
“The vessel was seized based on false allegations,” Eslami said in comments reported by state news agency IRNA. “We hope the release will take place soon.”
Iran’s semi-official Fars news agency, quoting unidentified authorities in Gibraltar, said the tanker would be freed by Tuesday evening.
However, a senior source in the government of British overseas territory denied that would happen on Tuesday.
Britain said that investigations into the Grace tanker were a matter for Gibraltar. The territory has denied Iran’s claim that the action was taken on the orders of Tehran’s longtime foe Washington.
“As this is an ongoing investigation, we are unable to comment further,” a British Foreign Office spokesman said.
The Gulf tanker crisis has added to worsening hostilities since Washington pulled out of Iran’s 2015 nuclear deal with six powers, under which Tehran agreed to curb its nuclear work in return for most international sanctions being lifted on it.
The Iranian capture of the Stena Impero drew condemnation from Britain and other European parties to the nuclear deal that have been trying to salvage it by shielding Iran’s economy from reimposed and toughened US sanctions.