Australian cricket star Chris Lynn served a one-month cocaine ban that has only now become public, after failing a drug test on the day he helped Northamptonshire win England's T20 Blast title.

The 36-year-old admitted to using cocaine over several hours following his side's quarter-final victory in July, with his suspension subsequently reduced after he completed a substance-abuse treatment program. 

Lynn served the ban from July 31 to August 30. The sanction emerged publicly on Friday, months after he had completed it and amid reports linking him with a Big Bash League move to the Melbourne Renegades.

The former Australian international provided a urine sample during T20 Blast Finals Day at Edgbaston on July 18.

He scored 39 in the semi-final and four in the final as Northamptonshire claimed the trophy for the third time.

Analysis at a World Anti-Doping Agency-accredited laboratory in France detected benzoylecgonine, a metabolite of cocaine.

Lynn subsequently acknowledged taking the drug on July 15 and into the early hours of July 16, several days before the test.

Earlier on July 15, he had retired hurt during Northamptonshire's quarter-final win over Gloucestershire after being struck on the foot by a low full toss from Duan Jansen.

England's Cricket Regulator accepted evidence that Lynn's cocaine use took place out of competition and was unrelated to sporting performance.

After the Blast, Lynn travelled to Sri Lanka for the Lanka Premier League, making one appearance for Galle Gallants before being ruled out with a leg injury on July 29.

Two days later, the regulator notified him of his positive test and imposed a provisional suspension.

Lynn responded on August 20, admitting the cocaine use and supplying evidence about when it had occurred.

The regulator initially pursued two charges under the England and Wales Cricket Board's anti-doping rules.

One was subsequently dropped because the concentration detected in his sample fell below the minimum threshold required for that charge.

The remaining breach carried a proposed three-month suspension. That was reduced to one month after Lynn provided confirmation he had completed a substance-abuse treatment program.

His suspension was deemed completed on August 30, with formal notice of the charges following on September 23. Lynn accepted the sanction.

Cocaine is prohibited in competition under the anti-doping rules and is also classified as a substance of abuse. 

The regulator's acceptance that Lynn used it outside competition, without a connection to sporting performance, was central to the penalty imposed.

Lynn has not played professional cricket since his brief stint in Sri Lanka.

His playing future is now back in the spotlight after he reportedly agreed to join the Melbourne Renegades for the upcoming BBL season. The signing has not been officially announced.

One of Australia's most recognisable T20 power hitters, Lynn played four one-day internationals and 18 T20 internationals for his country, with his most recent Australian appearance coming in 2018.