Libyan Prime Minister Abdullah Thinni was prevented by security officials at Labraq airport from catching a flight to Malta, the Libya Herald has reported.
Thinni, who heads the internationally recognised Libyan government based in Tobruk, had been due to come to Malta for a conference between the Libyan National Oil Corporation and a number of contractors.
Sources told the Libya Herald that the officials at the airport were carrying out orders from top military figures, seen as a reference to General Khalifa Hafter.
Meanwhile, Thinni's government said earlier today that it was recalling its team from U.N.-backed peace talks with rivals, complaining about amendments to a draft agreement meant to end their conflict - which has seen a rival government formed in Tripoli.
It was the latest setback for United Nations efforts to reach a deal by Sept. 20 over the crisis .
Libya's official government is struggling to woo oil majors in a bid to control oil revenue and force a rival Tripoli government into a U.N. peace deal because foreign clients are wary of breaking with the established state energy firm in the capital.
The battle over Libya's oil resources is at the heart of a conflict between the two governments and parliaments allied to a host of armed groups fighting for power four years after an uprising ousted leader Muammar Gaddafi.
The internationally recognised government, wants oil firms to discuss purchase contracts with its own officials instead of the state oil firm based in the capital, which is held by a rival group.
So far foreign oil buyers have sought to ignore the conflict by continuing to pay through the state's National Oil Corp (NOC) and the central bank in Tripoli, using a system in place for decades under Gaddafi.
By appointing its own NOC management and inviting firms to a conference (originally in Dubai) the east escalated the dispute to put pressure on the rival government in Tripoli to agree on a national unity government.
Thinni had already demanded in March that oil exports be paid for through new bank accounts in Dubai but no buyer has signed any deal because of legal concerns about proof of ownership. Contracts and geological data are stored at NOC Tripoli.
In the invitation to the Dubai conference, the eastern NOC chairman Naji al-Maraghi pointed out to oil firms that the state firm was based in the eastern city of Benghazi; not Tripoli, where several hundred staff work.