A POTENTIALLY explosive video has captured the moment South African captain Faf du Plessis took an extraordinary measure when shining the cricket ball on the final day of the second Test in Hobart.

Channel 9 cameras broadcast the Proteas skipper appearing to use saliva that had interacted with a lozenge, mint or lolly to shine the Kookaburra when Australia was in the middle of its embarrassing second innings collapse at Bellerive Oval.

The footage shows du Plessis fingering an item in his mouth before rubbing his digit on the shiny side of the Test match ball.

The video clip is certain to attract questions of potential ball tampering after Australian cricketers earlier this series raised their own concerns about their South African rivals’ ability to get the ball swinging during the first Test at the WACA.

Du Plessis was reportedly warned by umpires Aleem Dar and Nigel Llong about his team scuffing up the ball with their returning throws to keeper Quinton de Kock during the first Test.

The fill-in skipper has also previously been accused of ball tampering when he was fined 50 per cent of his match fee in 2013 in a Test series against Pakistan when broadcast cameras filmed him “rubbing the ball in the vicinity of the zipper of his trouser pocket”.

Under the MCC laws of cricket no artificial substance can be used to polish the ball.

Law 42 regarding fair and unfair play states that: “Any fielder may polish the ball provided that no artificial substance is used and that such polishing wastes no time”.

It follows revelations in 2008 from former English batsman Marcus Trescothick that England “cheated” during the 2005 Ashes series against Australia by using mint-induced saliva to keep the shine on the ball.

In his autobiography, Trescothick admitted to using Murray Mints in order to boost the longevity of the shine he was trying to put on the ball.

On the eve of the second Test, Du Plessis dismissed questions about his team’s ability to seemingly harness the dark arts of reverse-swing.

He described the presence of reverse swing as a non-issue. “We were watching the first innings and they got the ball to reverse in the 25th over. I was quite impressed,” said du Plessis, of Australia’s ability to swing the ball in Perth.

“I was trying to see how they were doing it because that meant they were doing something right. Twenty-five overs is very early for the ball to reverse. The Aussies did it really well.

“To say it was only for us is not true. I faced a brilliant spell from Mitchell Starc bowling around the wicket and reversing the ball. It was extremely difficult. They just lost more wickets so it was harder work for them.”

Australian quicks Josh Hazlewood and Mitchell Starc both professed their astonishment at the tourist’s ability to swing the ball earlier in the series.

“We’ve talked a bit about it, they got it going pretty well in both innings in Perth which is quite rare in Perth,” Hazlewood said.

“We tried our best to get it going and can usually get it going if conditions suit, it was a bit frustrating only getting a little bit of movement here and there.

“I think the hardness of the ball was another thing that frustrated us. Their balls seemed to keep their hardness for a lot longer and ours got that soft feel to it, it was tennis ball-like.

“There’s a few things to work on in the bowling department, especially around the ball.

“They’re obviously a well drilled unit with the reverse ball and bowl great areas with it. It’s a frustrating one but we’ll keep working on it.”