Simone Callahan, who reunited last December with the spin bowler known also for his womanising, told New Idea magazine she caught the spin bowler cheating on her while he was in London.
As Callahan got the couple's three children ready for school in Melbourne, she said a text dropped into the inbox of her mobile phone.
"Hey beautiful, I'm just talking to my kids, the back door's open," the message from Warne said.
"You loser, you sent the message to the wrong person," Callahan sent back.
She told the magazine the message confirmed her suspicions that Warne was again cheating on her, adding that he had told her there was someone else and apologised.
However, Warne issued a statement saying the couple agreed amicably to go their own ways nearly two months ago.
"There was no affair, nor anyone else," he said.
The 38-year-old Warne, who played for English county Hampshire this year, said he was looking forward to a quiet Australian summer and planned to spend time with his children and friends.
Warne took a world record 708 wickets in 145 Tests, but also had to endure numerous tabloid headlines for boisterous post-match celebrations, phone sex and drug scandals.
He and Callahan divorced in 2005, with Warne later saying his womanising was something he did to ease the loneliness of long cricket tours.
