Schwazer, who won the 50km gold at the 2008 Beijing Games, returned a positive result for a steroid, the Italian athletics federation said on Wednesday, six weeks after he returned from a near-four year doping ban to win the world title in Rome.
Schwazer denied any wrongdoing at a media conference and suggested he was a victim of sabotage, but Tallent, who was runner-up in Rome and edged for the Beijing gold by the Italian, was having none of it.
"Last time Schwazer held a press conference he lied and told made up stories," Tallent tweeted on Thursday. "Why would anyone believe him this time?" he added, with the hash-tag '#banschwazer'.
Schwazer was excluded from his London title defence after testing positive for the blood-booster EPO in 2012 and cried when admitting his guilt at a media conference.
Banned for three years and six months, he was given an additional six-month ban with three months suspended last year for evading anti-doping tests.
His ban expired at the end of April.
Tallent was presented with the London Games gold medal in Melbourne last week, four years after he finished runner-up behind a Russian drug cheat who was stripped of the title by a Court of Arbitration of Sport decision in March.
Schwazer's positive test has ignited hopes in Australia that Tallent could be due for more retroactive glory.
The Australian said he had lost focus at the world championships in Rome when he realised Schwazer was competing there after returning from his ban.
After receiving his Olympic gold in Melbourne, Tallent said he was uncomfortable with the idea of Schwazer competing at the Rio de Janeiro Olympics which start on Aug. 5.
"Unfortunately, there is an Italian who was banned just before London who has just come back from a three-year and nine-month ban, and we have question marks over him," he said.
(Reporting by Ian Ransom; Editing by Greg Stutchbury)
