South African crude oil imports from Iran rose to 3.37 billion rand in March from 2.8 billion the previous month, customs data showed on Monday, April 30 indicating Pretoria had not bowed to U.S. pressure to curb commercial links with Tehran, Reuters reported.

The Revenue Service said Africa's biggest economy imported 505,908 tonnes of Iranian crude in March, up from 417,188 tonnes the previous month.

South Africa has come under Western pressure to cut Iranian crude imports as part of sanctions designed to halt Tehran's suspected pursuit of nuclear weapons, although it has been unclear how diplomatically non-aligned Pretoria is responding.

Imports declined between October and January, when they reached zero, but have been rising again since February.

Senior energy and foreign ministry officials contradicted each other in March as to the status of Iranian imports. Iran has usually been South Africa's biggest crude supplier, accounting for a quarter of its oil imports.

According to the March data, crude imports totalled 1.6 million tonnes, with Nigeria supplying 38 percent, Iran 32 percent, Saudi Arabia 22 percent and Angola the rest.

The biggest South African buyer of Iranian crude used to be Engen, majority-owned by Malaysian state oil group Petronas, but the group said in April it had halted all imports of Iranian product.

Petrochemicals group Sasol, which took 12,000 barrels of Iranian oil a day, also said it had found new suppliers but has not named them.