A woman wanted by the FBI over a fatal hit-and-run has told an Adelaide court that she is "languishing in prison" in Australia eight months after her arrest.

Key points: Andrea Dorothy Chan Reyes is being held at Adelaide Women's Prison

Andrea Dorothy Chan Reyes is being held at Adelaide Women's Prison She was arrested by the Australian Federal Police in April

She was arrested by the Australian Federal Police in April Ms Chan Reyes is wanted by the FBI over a fatal hit-and-run in 2017

However, Magistrate David McLeod said Andrea Dorothy Chan Reyes could be released on bail if she was extradited to the United States.

Ms Chan Reyes, 33, is facing extradition after she allegedly hit and killed a cyclist, 46-year-old Agustin Rodriguez Jr, in January 2017 and fled the scene.

Documents from the United States District Court allege Ms Chan Reyes was travelling at a "high rate of speed" and dragged the victim about 270 metres under her sports car.

She flew to Hong Kong — where she had family ties — five days after the alleged fatal hit-and-run in a move the FBI claimed was "with the intent to avoid prosecution".

The FBI issued a warrant for her arrest in September 2017 and she was located and arrested in Adelaide in April this year.

She has been remanded in custody since.

Her lawyer Andrew Graham asked the Adelaide Magistrates Court to keep her behind bars for at least another two months in the hope of re-opening her bail application based on her deteriorating mental health and new evidence.

That new evidence was that she had booked a return flight to the United States and had also voluntarily undertaken a criminal history check before her arrest, the court was told.

"One might expect if someone was hiding from the authorities in America, they wouldn't provide their details at a police station so there could be a check done with an American law enforcement agency," he told the court.

The accused is 'not a flight risk'

Mr Graham said he understood that at least one change had been made to her return flight date which was contrary to the prosecution submission that she was "covering tracks" because there would not be the need for the extra change and spending money.

"Those two aspects would go towards an assessment of flight risk, it's for those reasons that I'm asking for an adjournment of a bail application," he said.

He told the court that Ms Chan Reyes could also be facing a federal charge and would be objecting to an extradition to the United States.

Magistrate David McLeod said Ms Chan Reyes could be released on bail if she was extradited to the United States.

"Well, it's going to see your client in custody for coming up to a year by the time all this is heard," he said.

"I'm anxious to move the matter forward based on the fact that your client's been languishing in custody since April for a matter she'd be out on bail on in America if she returned there.

"I'm also anxious… that prison isn't necessarily the best place for your client and the longer she's there the stronger your case becomes in respect to her mental health.

"Why this delay, it's all on your side of the fence?"

Paul Blair, the partner of FBI fugitive Andrea Dorothy Chan Reyes, leaves the Adelaide Magistrates Court. ( ABC News: Claire Campbell )

Supported in court by her partner

Mr McLeod asked Ms Chan Reyes if she agreed she was languishing in custody to which she said she was: "still languishing in prison".

Prosecutor David Billington said the bail application was "absolutely closed".

"This matter was not adjourned for there to be a review of what's happened to date," he said.

"Now what seems to be happening is an opportunistic attempt to produce yet further evidence.

"There's no explanation as to why those materials were previously unavailable… it seems to be an attempt to backfill what might have been a slightly better case."

Ms Chan Reyes regularly turned to her fiance, Paul Blair, and smiled and waved at him as she sat in the dock of the court.

Mr Blair previously told the ABC Ms Chan Reyes was arrested four days after they had become engaged.

He said he would stick by her throughout the court proceedings.

Today, outside court, he made no comment to the media.

Ms Chan Reyes will return to court in February.