Former England pacer Steve Harmison feels Australia's batting mainstay Steve Smith will always be remembered as a "cheat" for the infamous Cape Town ball-tampering scandal, irrespective of his incredible feats.

Smith has been England's tormentor-in-chief in the ongoing Ashes series, which Australia have retained after winning the fourth Test in Manchester on Sunday.

Smith is having a fairytale Ashes series, already accumulating 671 runs, including a double century at a staggering average of 134.20.

But that didn't stop Harmison from taking a dig at the former Australia skipper, who said Smith can never be forgiven for his ball-tampering act.

"I don't think you can forgive him," Harmison was quoted as saying by London-based sports radio station 'talkSPORT'.

"When you're known as a cheat - and he is, I'm not going to sugar-coat it, the three guys cheated - that's on your CV. You're marked and you take it to your grave. Whatever Steve Smith does, he'll always be remembered for what happened in South Africa," he added.

Harmison, who represented England in 63 Tests including all five games during the 2005 epic Ashes series, said Smith and his partners-in-crime David Warner and Cameron Bancroft will have to live with "cheat" tag all their lives.

"I can't see anybody's opinion changing on Smith, Bancroft, or Warner. Because of what they've done, they've tarnished the game," he said.