The South African Transport and Allied Workers' Unio head is being targeted over the ANC president's second term and billion-rand tenders.
Satawu has agreed to a wage deal, putting an end to the week-long road freight sector strike, it said on Monday.
The wage offer made to striking road freight workers was increased to 8% across the board after 5pm on Wednesday, Satawu said.
There are no signs of an end to the dispute between Satawu and the Passenger Rail Association of South Africa, the union said on Wednesday.
Metrorail trains will be running in Gauteng from Monday following a strike that left thousands of commuters stranded nationwide last week.