A surprise move by investigators is set to rock Victoria's spring racing carnival, with champion jockey Mark Zahra summonsed to publicly testify about a notorious race fixing scandal.

Fairfax Media can also reveal that controversial Sydney punter Eddie Hayson, who is at the centre of a rugby league match-fixing probe in NSW, has been ordered to hand over betting records to Victorian authorities.

Australia's most controversial jockey, Danny Nikolic, who has successfully overturned a racetrack ban issued by Victoria's police chief commissioner, will on Monday launch a legal battle to have his jockey's licence returned in time for Australia's biggest racing carnival.

Next Monday's action against Zahra and Hayson is aimed at keeping Nikolic from riding in the spring carnival, in what is looming as a landmark battle for Victoria's sports integrity regime.

But in an explosive move to counter Nikolic's actions, stewards have issued subpoenas in an attempt to force Zahra to reveal publicly and on oath the inside story of the infamous Smoking Aces race-fixing affair.

The affair involved police phone taps in 2011 recording Nikolic allegedly arranging to fix a Victorian race in order to deliver big returns to his associates who had bet on the race. Nikolic has always denied the allegation and the police never pressed charges.

Zahra is suspected by police to hold the key to unlocking the scandal if he is prepared to testify openly about his knowledge of the affair.

Fairfax Media can reveal that in 2012, Zahra testified on oath in a secret Australian Crime Commission hearing that Nikolic offered him a $3000 kickback to help fix the race.

This means Zahra will be under intense pressure when called to testify on Monday at the Victorian Civil and Administrative Tribunal.

Zahra's lawyer, Tony Hannebury, said his client would fight the subpoena to testify about Nikolic, that any suggestion by racing authorities that Zahra had been intimidated by Nikolic would be rejected and that his client supported the Australian Jockeys Association's backing of Nikolic's bid to ride again.

The fight to keep Nikolic away from the spring carnival also involves Eddie Hayson, who earlier this year became the centre of a media storm over allegations he may have used inside information to bet on NRL matches, including those featuring players close to him. Hayson denies any wrongdoing.

Fairfax can reveal that Hayson's betting records and CCTV vision from inside a TAB outlet suggest he used a TAB account linked to Danny Nikolic to bet tens of thousands of dollars on AFL matches and horse races since early 2015. The use of a third party account obscured Hayson's involvement in the betting, making it difficult for sports integrity investigators to track suspicious betting.

Victorian stewards have used subpoena powers to compel Hayson to hand over documents detailing his relationship with Nikolic in an attempt to build a case that the jockey poses an integrity risk to racing.

The prospect of Nikolic riding again is regarded by senior police and racing officials as disastrous for Victoria's sports integrity regime.

The case may force the Andrews government to legislate to enable the police chief commissioner and sporting administrators to ban people from regulated gaming or sporting sectors using a "fit and proper" test.

But supporters of Nikolic and civil libertarians argue that in the absence of a serious criminal conviction, such bans are unjust.

Earlier this year, Nikolic succeeded in a Supreme Court appeal aimed at overturning a chief commissioner's ban from racetracks.

The ban was overturned because the court found Nikolic was denied natural justice when police refused to disclose the secret intelligence the chief commissioner had relied on to ban Nikolic on character grounds.