The Soweto giants have already unveiled Velebayi as their player, even assigning him a jersey number, just a day after the Premier Soccer League (PSL) Dispute Resolution Chamber (DRC) cleared the move.
Spurs maintain they still have a binding contract with the 22-year-old, despite their relegation to the amateur ranks.
However, on Monday, the DRC ruled that the agreement was null and void because Spurs no longer hold professional status.
Wasting no time, Velebayi travelled to Johannesburg to sign for Amakhosi and begin training at Naturena.
Sources indicate Spurs, furious over the DRC verdict, have already paid the R35,000 arbitration fee required by SAFA to appoint an arbitrator to review the case.
The Urban Warriors hope the ruling will be overturned.
SAFA is expected to confirm a hearing date once an arbitrator accepts the case. Meanwhile, Chiefs have moved quickly to register Velebayi so he can be available for selection.
Spurs are also awaiting two further rulings on similar cases involving Luke Baartman and Liam Bern, both seeking to be declared free agents.
Baartman is believed to have agreed terms with Chiefs, while Bern, as confirmed by AmaZulu president Sandile Zungu, has a deal in place with Usuthu.