A woman assaulted by Danny Nikolic denies suggesting the jockey had something to do with the murder of his former father-in-law Les Samba.

Rikki-Lee Hull told Nikolic's appeal to regain his jockey licence that the rider grabbed her by the hair during a heated exchange at a Melbourne hotel in March 2011.

Hull, who was dating jockey Mark Pegus at the time, denied making a reference to Samba's murder a few weeks earlier.

"No, not at all. Not that I recall at all," Hull told the Victorian Civil and Administrative Tribunal.

Nikolic's barrister Julian Burnside QC asked Hull if she said words to the effect that Nikolic probably had something to do with Samba's murder.

Hull repeatedly denied the suggestion.

"I'm 100 per cent sure I wouldn't have said something like that," she said on Thursday.

Samba was killed by an unknown gunman in Melbourne in February 2011.

Nikolic was interviewed by police investigating the racehorse owner and trainer's murder and cleared of any involvement.

Hull said she had tried to leave the nightspot to avoid Nikolic as she was upset about an altercation he had with Pegus in January 2011.

"Things got heated between us and that's when Danny grabbed me," she told VCAT.

"From memory what he said was I was to keep my mouth shut. If not, it wasn't going to happen there, it was going to happen elsewhere."

Hull said she told Nikolic she did not want to have anything to do with him.

She agreed her words to Nikolic appeared to upset him but said it was about the Pegus altercation and she would not have said anything about the Samba case.

Nikolic has told VCAT he pushed Hull away and may have grabbed some of her hair, but it was rubbish that he grabbed a fistful of her hair while verbally abusing her.

Nikolic was placed on a good behaviour bond without conviction after pleading guilty to assaulting Hull.

Racing Victoria chief steward Terry Bailey is expected to give evidence to VCAT on Friday.