An academic whose work has helped shape South Australia's response to Covid-19 has denied assaulting a university colleague with whom he had sex on a retreat.

Professor Joshua Ross insists his sexual activity with Dr Giang Thu Nguyen at the Stamford Grand Hotel in the Adelaide beachside suburb of Glenelg was consensual. 

Dr Nguyen, who works with Professor Ross at the University of Adelaide, is alleging she was sexually harassed and the university failed to adequately investigate her complaint.

She is seeking $970,948 in damages, lost wages, entitlements and future expenses at the Civil and Administrative Tribunal over alleged breaches of the Equal Opportunity Act.

Her compensation case against the university and Professor Ross began being heard by the tribunal on Wednesday,  reported.

Dr Nguyen claims she was 'not able to consent, and did not consent' when Professor Nguyen performed sex acts on her because she was too intoxicated.

Professor Ross asserts Dr Nguyen initiated sexual contact by kissing him and was a 'willing consensual partner... cognisant and capable of consent', according to documents seen by the The Advertiser.

Professor Ross, from the university's School of Mathematical Sciences, has provided Covid modelling to SA Health which was used to inform decisions about border closures and vaccination.

Dr Nguyen, who is a senior lecturer in the same department, is also the director of gender, diversity and inclusion at the Faculty of Engineering, Computer and Mathematical Sciences.

Both academics attended a three-day retreat held by the Australian Research Council Centre of Excellence for Mathematical and Statistical Frontiers in late October 2019.

Dr Nguyen says in court documents she had consumed alcohol and 'became significantly intoxicated' while socialising after the conference.

A group had dined at Sammy's on the Marina then had drinks at the Moseley Bar and Kitchen and the Glenelg Pier Hotel until 2am. 

'By around this time, [Dr Nguyen] was extremely intoxicated to the extent that she experienced significant memory impairment, tata kelola ti loss of balance and coordination, slurred speech and slow decision making,' court documents state. 

Dr Nguyen alleges Professor Ross had sexual intercourse with her in his hotel room between 1.45am and 5am.

'Due to the level of Dr Nguyen's intoxication, she was not able to consent and did not consent to the acts of sexual intercourse,' the court documents say.

Dr Nguyen alleges when she woke naked on a couch in Professor Ross's room and saw him asleep in his bed she vomited on the couch and crawled to the bathroom. She later made a complaint to police.

Professor Ross says he voluntarily provided a statement to police and was told in March 2020 detectives would not be charging him with any offence. 

His response to Dr Nguyen's claim states the university said it was satisfied he had engaged in 'no serious misconduct'.

According to Dr Nguyen, the alleged assault by Professor Ross resulted in 'offence, humiliation and intimidation' due to her extreme intoxication and because she was his subordinate.

Dr Nguyen says she suffers post-traumatic stress and is unable to return to employment, and accuses the university of not providing a safe workplace.

'The university has harboured a system, culture or practice of not investigating complaints of sexual harassment with requisite seriousness,' she alleges.

Documents filed on Professor Ross' behalf state on the night he had sex with Dr Nguyen the pair 'sat very closely next to each other on a sofa' and she initiated a kiss on the lips.

'At all material times, Dr Nguyen was cognisant and capable of consenting to sexual activity,' Professor Ross claims. '[Dr Nguyen] was a willing consensual partner in sexual relations.'

The university stands by its findings that there was insufficient evidence to conclude a sexual assault had occurred and says it would not be responsible if it did.

It further denies Professor Ross is Dr Nguyen's supervisor and says it can ensure the two academics are never rostered on at the same time on the campus.