Pirates in June released the left-back after he saw limited game-time in an 18-month stint at Mayfair.
KickOff.com later learnt he was in negotiations with Usuthu. And according to a source in the team, Van Heerden has finalised terms with the Durban-based outfit.
"Yes, Marc is back with us, he has concluded everything with the club," says the informant.
He adds: "He only started training with the team this week, he started on Monday to be exact."
The 30-year-old Van Heerden spent eight years with AmaZulu before stints at Chippa and Bucs.