The National Treasury is to take control of finances in North West and will launch an investigation into contracts and tenders issued by embattled premier Supra Mahumapelo's administration.

Amid widespread protests in the province against alleged corruption by Mahumapelo, a minister with direct knowledge of the matter told the Sunday Times that a team sent by Finance Minister Nhlanhla Nene would investigate all suspicious tenders and contracts over R10-million.

The Treasury would play a "big brother" role and scrutinise all spending in North West, not only that of the provincial health department, the minister said.

The cabinet decided this week to place the health department under administration by the central government while the ANC mulls Mahumapelo's fate.

"We are taking the money away," said the minister, who asked not to be identified. "He [Mahumapelo] still has constitutional powers as premier ... but we have to deal with it politically."

Treasury officials had not responded to questions at the time of going to press.