A tanker carrying crude oil from Iraqi Kurdistan reappeared unladen on Aug. 19 about 30 kilometres off the coast of Israel, ship tracking data on Reuters showed.
This is the second time the Kamari has appeared in the area in the last two weeks carrying Kurdish oil.
The tanker Kamari was partly laden north of Egypt's Sinai on Aug. 17, tracking showed, before it turned off its satellite transponder until early on Aug. 19. It was not possible to determine where the oil had been delivered to or who the buyer was.
A spokesman for the Kurdistan Regional Government (KRG) Ministry of Natural Resources did not immediately respond to phone calls and emails seeking comment on Wednesday. The KRG has previously denied selling oil to Israel "directly or indirectly".
The tanker loaded the Kurdish crude at the Turkish port of Ceyhan around Aug. 8, and made a partial delivery to Croatia via a ship-to-ship transfer last week.
Hungary's MOL Group said on Monday that it had purchased 80,000 tonnes, just under 600,000 barrels, of Kurdish crude, which discharged at Croatia's Omisalj port at the weekend. The company has exploration and production assets in Kurdistan.
Iraq's central government in Baghdad has repeatedly called independent Kurdish exports "smuggling", saying only state marketer SOMO has the right to sell Iraqi oil. The KRG says the Iraqi constitution allows it to sell oil independently of Baghdad.
Since the KRG began exporting major volumes via its pipeline, Baghdad has actively tried to block sales and has so far been successful in stopping one to Morocco and another to the United States. Baghdad has also cut the Kurds out of the country's budget since January.
Despite the setbacks, an increasing number of cargoes are now finding buyers.
The loss of funds and limited revenues from its oil sales come at a crucial moment for Iraq as the Kurdish armed forces, known as peshmerga, have become the main body able to effectively combat the advance of extremist Sunni fighters of the Islamic Caliphate.
The United States and several EU countries have either started or have pledged to supply arms and ammunition to help the Iraqi Kurds. United States air strikes have helped Kurdish forces push back the Islamic State in the past two weeks.
Previous Tanker Movements
Two weeks ago, the same 1 million barrel tanker loaded Kurdish oil at Ceyhan before sailing to a point just under 200 km (125 miles) off the Israeli and Egyptian coasts.
Reuters AIS Live ship tracking showed the ship was fully loaded, based on its draft in the water. After turning its satellite tracking off on Aug. 1, the ship reappeared four days later sitting far higher in the water - indicating it had unloaded its cargo of disputed oil.
It was not possible to determine which port the oil aboard the Kamari had been delivered to or who the buyer was. In June a cargo of Kurdish oil that sailed from Ceyhan aboard the United Emblem Suezmax tanker was delivered into Israel after being transferred at sea to another ship.
Israel's prime minister and several officials openly called for the recognition of an independent Kurdistan this summer, though a Kurdish diplomat later played down coordination between the two countries.
In June, the SCF Altai tanker delivered 1 million barrels of Kurdish crude to Israel's Ashkelon port for an unknown buyer. It was the first successful delivery of Kurdish oil from the region's new pipeline to Turkey, though the KRG denied selling oil to Israel directly or indirectly.
(By Julia Payne, Additional reporting by David Sheppard; Editing by Michael Urquhart)