South African sound engineer Nick Greyling, from a television sports crew, has been released one week after his kidnapping in Nigeria, the foreign ministry said Tuesday.

"I wish to thank M-Net Supersport and Greyling's family in particular for their cooperation and confidence shown in the South African authorities during this unfortunate incident," foreign minister Maite Nkoana-Mashabane said in a statement.

"In the same vein, we take this opportunity to welcome Greyling back home to be re-united with his family."

A security source in Nigeria said a 15 million naira (100,000 US dollars) ransom was paid, negotiated down from 120 million naira. South African officials declined to say if a ransom was paid.

Gunmen on March 1 snatched three M-Net Supersport crew members after ambushing a bus carrying them to the airport in Owerri, the capital of Imo State, which neighbours the oil hub of Rivers State.

The crew were returning from covering a football match in the nearby city of Enugu, 150 kilometres (94 miles) away.

Alexander Effiong, a Nigerian cameraman, fled from his abductors one day after the kidnapping.

Kidnappings are relatively common in Nigeria's restive oil-rich south, where oil workers were originally targeted. In recent months, kidnappings have spread to other parts of the country, including Lagos.