
The all-time leading run-scorer in the Big Bash League tested positive during a routine anti-doping test on July 18 during the T20 Blast Finals Day in England.
He was a Northamptonshire player at the time, with England's Cricket Regulator only revealing the outcome on Friday.
"The Cricket Regulator has imposed a one-month suspension on former Northamptonshire Steelbacks cricketer Chris Lynn," it said. "The period of suspension has now been served."
Lynn, 36, tested positive for low levels of benzoylecgonine, a metabolite of cocaine, and admitted the charge.
His ban was reduced from three months after he completed a rehabilitation program and the regulator agreed it was out-of-competition use and not related to sporting performance.
Lynn played 18 T20s for Australia and four one-dayers.
Australian media said he was poised to join the Melbourne Renegades for this season's Big Bash League which gets underway next month, reports BSS.