Iranian sources said that the Iranian tanker "Grace 1" detained in Gibraltar will be released within 48 hours.
"Following legal and diplomatic efforts, the Grace 1 oil tanker, which British forces illegally detained in the Strait of Gibraltar, will be released within the next 48 hours," state television quoted the sources as saying.
For its part, Britain said on Tuesday that the investigation into the Iranian oil tanker "Grace 1" is a matter for the authorities of Gibraltar.
"The ongoing investigation into Grace 1 is a matter for the Gibraltar government," a Foreign Office spokesman told Reuters.
The agency "Fars" Iranian has said, earlier, that the Iranian ship detained by Gibraltar will be released this evening.
The agency, citing sources in Gibraltar, said the tanker, detained five weeks ago "Grace 1", would be released this evening. A source in the Gibraltar government denied Iranian reports that the tanker had been released.
The news agency "Reuters" a source in the government of Gibraltar that the Iranian reports are incorrect.
The Gibraltar authorities had confirmed, earlier on Tuesday, it is seeking to defuse tension with Iran since the detention of the tanker "Grace 1".