Former South African fast bowler Fanie de Villiers says he instructed camera operators to look for Australian ball tampering on day three of the third Test, having suspected the Australians were using underhanded tactics.

De Villiers is working for a broadcaster in South Africa and claims he believed the tourists must have been up to something given how early they were getting reverse swing.

Former South African fast bowler Fanie De Villiers. Credit:Craig Golding

Ultimately his suspicions proved to be correct, with cameras spotting Australian fieldsman Cameron Bancroft’s now-infamous yellow tape, leading to Bancroft hiding the tape in his pants before ultimately coming clean alongside then captain Steve Smith.

"I said earlier on, that if they could get reverse swing in the 26th, 27th, 28th over then they are doing something different from what everyone else does," de Villiers told RSN Radio on Monday.