Steve Smith is one of three Australian players ordered to return home following the ball tampering scandal. Photo: Nic Bothma/EPA

SYDNEY – When Steve Smith took over as Australia skipper from Michael Clarke in 2015, he vowed to continue Australia's brand of "hard, aggressive" cricket -- without crossing the line.

Just 32 months on, the 28-year-old has been sent home in disgrace from a tour of South Africa after masterminding a ball-tampering scandal seen as breaching the standards he promised to respect.

Smith's stunning fall from grace - on the heels of high praise for his recent performances in the Ashes when he was described as the "best since (Don) Bradman" - is an extraordinary turn of events for the world's premier Test batsman.

Steven Peter Devereux Smith, born in Sydney in 1989, made his first-class debut for New South Wales in 2008 when he was regarded more as a promising leg-spinner.

Two years later, he was given his Baggy Green cap against Pakistan, where he batted at number eight. 

Dropped during Australia's home series Ashes loss to England, Smith was recalled to the Test team in 2013. His maiden Test century came at the expense of England in the fifth Test at The Oval.

Steve Smith took over as Australia skipper from Michael Clarke in 2015. Photo: Nic Bothma/EPA

'Extraordinary talent' 

The hundreds started to pour in and when he filled in for then-skipper Clarke, who was injured, on the 2014-2015 tour of India, he again impressed with centuries in all four Tests.

By the time Smith was anointed Australia's 45th Test captain in 2015, he was hailed by former national selector Rod Marsh as a "fine young man with extraordinary talent, excellent leadership qualities and a terrific temperament".

Yet even as the batting accolades piled up for the unorthodox right-hander, questions were raised about his leadership acumen.

In 2016, he was fined 30 percent of his match fee for dissent after an obscenity-laced rant against the umpires during the second Test against New Zealand in Christchurch. 

He pledged to be a better leader, but last year Smith drew criticism from India captain Virat Kohli for looking to his dressing room for help while deciding whether to call for a review after his lbw dismissal in the second Test in Bangalore.

He later described the moment as a "brain fade".

The tensions with other teams grew, and England bowler James Anderson blasted the Australians as bullies who overstepped the line in the home 2017-18 Ashes series.

Tarnished reputation

In the current series against South Africa, Smith stirred the pot when he appeared to cast doubts on the International Cricket Council's appeal process after a ban on South African bowler Kagiso Rabada for bumping him was lifted.

Vice-captain David Warner - also exiled with Smith over the ball-tampering plot - was fined for a confrontation with Quinton de Kock during the series.

But the ugliness surrounding the series was set to take a darker turn when Smith sat down with Cameron Bancroft at the press conference after the third day of the third Test at Newlands on Saturday.

Bancroft, caught on TV appearing to rub yellow tape on the ball, admitted trying to change its condition while Smith said the team's "leadership group knew about it".

Bancroft was docked three demerit points and 75 percent of his match fee by the ICC, while Smith copped a one-match ban and was fined his entire match fee.

James Sutherland, CE (Cricket Australia) addresses the media on Tuesday. Photo: Samuel Shivambu/BackpagePix

The penalties were largely viewed as too light by shocked Australians, and Cricket Australia chief James Sutherland said on Tuesday that further punishments for the three players would be announced "within 24 hours".

The biggest challenge now for the gifted batsman will be off the field, as he seeks to rehabilitate a badly tarnished reputation and avoid being remembered as a cheat rather than for his incredible feats on the pitch.