"Mbili was one of the movement's hardest working and committed cadres in Parliament," Motshekga said in a statement.

"He was extremely detail-oriented and as part of the public accounts committee, Scopa, pursued parliamentary oversight with great vigour and fearlessness. He embodied the calibre of a cadre the ANC envisaged to accomplish the goals of the activist Parliament.

"His untimely death has indeed robbed the movement and the people of South Africa of an outstanding and loyal servant. We extend our deepest condolences to his family, friends, and comrades," Motshekga said.

Mbili joined the National Assembly in 2006, representing his constituency of Hibberdene in KwaZulu-Natal.

He participated in a number of parliamentary committees, including the portfolio committee on finance, and recently, Scopa, which he also served as whip.

Previously, Mbili chaired the ANC's Kwa Dabeka branch in KwaZulu-Natal from 1990 to 1994.

From 1999 to 2003, he served in the regional executive committee and the regional working committee of that province's lower region.