Sweden's Stena Group is hoping to overturn a Danish court verdict in a row dating back to the sale of a seized tanker cargo in 2013.
The Stena Oil unit has lodged an appeal to the Supreme Court in a bid to win a $6.5m compensation battle with Danish bunker and tanker group Monjasa.
Monjasa bought 10,000 tonnes of Stena's oil confiscated by the government of Sao Tome and Principe, following what the African nation said was an illegal transfer between two Stena-chartered tankers.
Stena Oil alleges Monjasa acted in bad faith by acquiring the oil.
But Denmark's high court ruled last month that Stena has no claim against Monjasa.
Monjasa told TradeWinds: "We had expected this clear verdict by the High Court of Denmark. Since 2013, we have maintained Monjasa’s legitimate right to act in accordance with a definitive ruling by a sovereign state’s Supreme Court."
Long legal nightmare
The legal nightmare began for Stena when the 10,700-dwt Duzgit Integrity (built 2008) tried to transfer the oil to the 13,100–dwt Marida Melissa (built 2009) in March, 2013, seven miles from shore.
The country’s law stated transfers could only be carried out 20 miles (32 km) from shore.
In October, the seized cargo was sold by the state to Monjasa for $3m.
Stena Oil told the high court that it had lost the cargo due to "state-run piracy".
The Permanent Court of Arbitration in The Hague later ruled the penalties imposed by the island state were disproportionate and unreasonable.
But the Danish court said that could not justify Monjasa being liable.
The masters of both vessels were sentenced to three years in jail, or two years of probation if their employers came up with $6.5m within 30 days.
The Marida Melissa was owned by Marida Melissa Schiffahrts of Germany and Duzgit Integrity by DSM of Turkey.
'Absurd' verdict
Defence lawyers said the convictions were "absurd".
One master said he had received guidance from a Sao Tome official to enter its waters.
Metin Duzgit, board member of the Turkish owner, told TradeWinds at the time that the Duzgit Integrity was chartered by Stena Oil in March 2011 and was due to go through a special survey at the end of March 2013.
The charterer had, therefore, requested the ship to deliver some of its equipment and 1,500 tonnes of gasoil to the other tanker.
Because of the need to use a crane to make the ship-to-ship transfer of the equipment, and in order to avoid any potential accidents caused by currents or waves, the two masters agreed to meet 7 nautical miles (12.9 nautical km) north of Sao Tome.
According to Duzgit, the first vessel to arrive at the rendezvous point was his company’s ship, which was approached by a coastguard boat soon afterwards. On being asked if permission was given for the transfer operation, the coastguard boat gave approval, Duzgit claimed.
After the arrival of the second vessel, the ships were again approached by the coastguard, this time leading to them being told to sail to the anchorage area of Sao Tome.
