The Ratna Shradha is one of at least three tankers forming part of some $815 million in oil revenues that South Sudan's President Salva Kiir accused Sudan of "looting" and which the government of Khartoum said provided compensation for unpaid transit fees.
"The cargo was scheduled to arrive at 9 a.m. today, and it should have arrived by now," said a Coast Guard official at Kiire port, which is operated by JX Nippon Oil & Energy .
At least two traders said the cargo had been bought by JX Nippon Oil.
Reuters reported this month that Geneva-based Trafigura, the world's third largest oil trader, bought oil that the South Sudanese government claims was seized by its northern neighbour and former civil war foe.
Landlocked, war-ravaged South Sudan must pump its oil to the Red Sea via a pipeline across Sudan to Port Sudan to earn oil revenues that bring in 98 percent of the seven-month old country's income.