Australia batsman Steve Smith 'shocked and disappointed' by accusations he cheated against India

Video footage from the stump camera showed Smith dragging his boot across the crease during drinks break while tourists batted on final day of tense match that ended in draw

Australian captain Tim Paine, left, said that Steve Smith did not deliberately scuff up the crease during the final day of the third Test against India. AP

Australia batsman Steve Smith says that he was "shocked and disappointed" by accusations that he deliberately scuffed-up the crease during the final day of the third Test against India on Monday.

Video footage from the stump camera of Smith dragging his boot across the crease on a tense final day of the match went viral on social media and some former players accused him of gamesmanship at best, cheating at worst.

Former England captain Michael Vaughan described the incident as "very, very poor" on social media.

But Smith insisted he had done nothing wrong. "It's something I do in games to visualise where we are bowling, how the batter is playing our bowlers and then out of habit I always mark centre," he told News Corp on Tuesday.

"It's such a shame that this and other events have taken away from what was a great batting performance by India yesterday."

Australia captain Tim Paine also denied Smith was guilty of any gamesmanship at the Sydney Cricket Ground.

Paine said Smith, who was stripped of the Australian captaincy and banned for a year in 2018 for his part in the Newlands ball-tampering scandal, had been upset by the allegations.

"I know he's really disappointed with the way it's come across," Paine told reporters on Tuesday. "If you've watched Steve Smith play Test cricket, that's something that he does every single game five or six times a day.

"He's always standing in the batting crease shadow batting. As we know, he's got those many Steve Smith quirks and one of those is he's always marking centre.

"He was certainly not changing [Rishabh Pant's ] guard and if he was, that's something that the Indians would have kicked up a bit stink about at the time."

Paine, who also apologised for his own conduct during the Test, said Smith might have to give up the practice given how it was interpreted.

"It's one of his mannerisms, he does it a lot, he was marking centre he wasn't by any stretch of the imagination trying to change guard or anything like that," he added. "It's something that he might need to look at because of the perception of it."

India pulled off a memorable draw in a tense third Test in Sydney that left the series level at 1-1 heading into the fourth and final Test in Brisbane, starting on January 15.

Paine apologised for his own actions during the final day, saying his sledging of Ravichandran Ashwin fell short of the standards he has set for the team.

"I want to apologise for the way I went about things, I'm someone who prides himself on the way he leads this team and yesterday was a poor reflection of that," he said.

"My leadership wasn't good enough, I let the pressure of the game get to me. Yesterday, I fell short of my expectations and my team's standards.

"I'm human, I want to apologise for the mistakes I made yesterday ... we've set really high standards over the last 18 months and yesterday was a bit of a blip on the radar."

The Test was also marred by allegations India were racially abused by sections of the SCG crowd.

Cricket Australia apologised to the India team on Sunday and investigations are under way with tough action promised against the culprits.