Andrea Dorothy Chan Reyes has appealed to the Full Court of the Federal Court against an earlier ruling denying her release from custody in Australia because of the delay in returning her to the US within a mandated two-month period.

Andrew Culshaw, for Chan Reyes, told the court on Friday that US officials had provided no specific evidence to support their position.

"The state of the evidence from the United States rises no higher than the broad assertion that the pandemic has created difficulties," he said.

"There is no specific evidence as to precisely what it is the pandemic has prevented from being done or specific evidence to the diversion of human and other resources from the extradition of Ms Chan Reyes."

Mr Culshaw said it was not reasonable to simply say there's a pandemic which makes travel dangerous without making efforts to mitigate any risks involved.

He said his client was also denied the opportunity to "scratch the surface" of the US position because nobody from the justice department provided material on which they could be cross-examined.

In his ruling earlier this year, Justice Richard White found that given the restrictions imposed by COVID-19, it was reasonable that US marshals had not come to Australia to take Chan Reyes back.

"This is not a case in which the US did nothing to give effect to the extradition until close to the expiration of the two-month period and only then found itself in difficulties," the judge said.

"It had been acting with the intention of giving effect to the extradition well within the two-month period and had made plans to do so."

But Mr Culshaw said while Australia had been doing what it could to facilitate the return of his client, it was his position that the US did not take up those invitations.

He also questioned assertions related to the need for marshals to quarantine for 14 days if they came to Australia, when in fact, they would only need to isolate for any period they were in the country, up to a period of two weeks.

Chan Reyes was first arrested in Australia on a US warrant in April 2018.

Documents later released by Adelaide Magistrates Court alleged she killed a cyclist, 46-year-old Agustin Rodriguez Junior, in a car crash in January 2017.

She is accused of dragging the man nearly 300 metres before he was dislodged and then driving away.

In court appearances last year she sought to be released on bail but her applications were refused, with a magistrate ruling she would be a flight risk.

The Federal Court appeal was continuing.

Australian Associated Press