Smith and teammate David Warner have faced hostile crowds since returning from year-long bans. Photo: Andrew Boyers/Reuters

Smith and teammate David Warner have faced hostile crowds since returning from year-long bans for their roles in a ball-tampering scandal in South Africa last year.

A section of the predominantly Indian crowd at the Oval in London booed Smith on Sunday when the Australian was stationed at third man.

Kohli, who went on to score a typically fluent 82, walked towards the crowd with his hand raised to draw their attention, gestured that they should applaud the Australian instead of booing him, then walked back to resume batting.

The International Cricket Council shared the video on its Twitter handle calling it "absolute class".

"I think what's happened has happened long back. The guy is back, he's trying to play well for his side... It's not good to see someone down like that, to be honest," Kohli told reporters.

"We've had issues in the past. We've had a few arguments on the field. But you don't want to see a guy feeling that heat every time he goes out to play.

"What's happened has happened. Everyone has known that. He's come back. He's worked hard. He's playing well for his side now."

Smith's 69 was the highest score in Australia's unsuccessful chase against India who won the high-scoring contest by 36 runs.

Kohli said he apologised to Smith for what the India fans had done.