Aaron Phangiso has been banned from bowling just two weeks before South Africa's opening World Twenty20 match against England after his action was deemed to be illegal.
The left-arm spinner was last week reported for a suspected illegal action following the Lions' Momentum One-Day Cup semi-final win over Warriors on Wednesday.
Phangiso, included in the Proteas' World T20 squad as back-up to Imran Tahir, underwent independent tests at an ICC-accredited laboratory in Pretoria and the 32-year-old failed to demonstrate a legitimate action.
Proteas spin bowling coach Claude Henderson and Cricket South Africa (CSA) high-performance manager Vinnie Barnes will now work with Phangiso to try and ensure he is cleared to bowl ahead of the World T20 in India.
"The timing of this issue for Aaron and for our World T20 squad is clearly inopportune but we need to deal with it," CSA chief executive Haroon Lorgat said.
"We will work hard to remedy Aaron's action and have him retested as soon as practically possible. We are fortunate to have an ICC accredited Laboratory in South Africa and this will certainly make a quick turnaround possible."
The spinner made headlines for the wrong reasons in January when it emerged he was banned from boarding a flight for being drunk and disorderly last October, while he last week apologised after being caught on camera imitating snorting drugs while in South Africa's dugout for the second T20 international against England.
Phangiso, who has played 16 one-day internationals and nine T20s, will play no part in the three-match T20 series against Australia - which starts on Friday.