Malaysian state-owned oil giant Petronas Monday denied any knowledge of alleged oil theft by the consortium it belongs to which is in the middle of a bitter dispute between Sudan and South Sudan.

South Sudan last month expelled the Chinese head of the country's largest oil firm, Petrodar, charging he colluded with former civil war foe Sudan to "steal" millions of barrels of its oil.

Petronas is a major shareholder in Petrodar along with Chinese state firm China National Petroleum Corporation.

Petronas president and CEO Shamsul Azhar Abbas denied knowledge of oil theft when asked for comment in the Malaysian capital Kuala Lumpur.

"That is subject of their investigation. As far as we are concerned on the ground there is no such thing happening," he said at a news conference to announce Petronas corporate earnings.

South Sudan's expulsion of Chinese national Liu Yingcai came after an investigation by the world's newest nation into millions of barrels of oil that South Sudan claims Khartoum stole.

Last month South Sudan vowed to halt oil production of around 350,000 barrels per day until Sudan repaid 2.4 million barrels of southern crude it confiscated from pipelines running through the north to its Red Sea port.

South Sudan split from the north last year but while it has most of the oil, Khartoum controls the pipeline and has access to the sea, sparking a furious argument and fears of renewed conflict.

Juba has accused oil companies operating on its territory -- which until last year had previously been working with officials in Khartoum -- of underreporting the number of oil wells, and aiding the north's confiscation of crude.

Petrodar has previously rejected such accusations.

China is a key ally of Khartoum's and major buyer of Sudanese oil.