Earlier today, Reuters news agency reported that a spokesman for the Gibraltar government, which seized Grace 1 at its ports, said, "We continue to work to quell the controversy over Grace 1 tanker seizure".
"As this is an ongoing investigation we are unable to comment further".
However, a senior Gibraltar official, speaking anonymously due to protocol, told the Associated Press that suggestions the tanker could depart on Tuesday night were "untrue".
Two weeks after the Grace 1 was detained, Iran's Islamic Revolutionary Guards Corps seized British tanker Stena Impero near the Strait of Hormuz for alleged marine violations.
Tensions have risen between Iran and the West after U.S. President Donald Trump pulled out of a 2015 landmark nuclear agreement which curbed Tehran's atomic program in return for an easing of economic sanctions.
Gibraltar said on Tuesday it was seeking to de-escalate issues arising with Iran since the detention. Britain considers that action to have been retaliation.
He noted that Iranian vessels, both oil tankers and merchant ships, are commuting under normal conditions in global waters despite some difficulties.
Iranian President Hassan Rouhani had warned London that it will definitely pay the price for the illegal seizure of Grace 1 in worldwide waters.
Britain has joined forces with US President Donald Trump to establish a maritime security mission in the Gulf to protect vessels, though Prime Minister Boris Johnson said the United Kingdom will not participate in sanctions against the Middle East nation.