A witness was arrested and another warned by the coroner during the opening day of the inquest into the death of Indigenous man, Jari Wise.

Mr Wise died on February 29, 2020 near the southern Tasmanian town of Huonville after being hit by a speeding car which was being driven by his former partner, Melissa Oates, who was drunk at the time.

Ms Oates was convicted of dangerous driving, drink driving and failing to stop and assist in an accident, however no legal responsibility was attributed to her for Mr Wise's death.

After Mr Wise's family called for an inquiry into his death which was subsequently ordered by former Tasmanian Attorney General, Louise Archer, the inquest is seeking to determine whether Mr Wise stepped in front of the car which killed him.

The inquest's first day was thrown into turmoil after witness Jessica Hosking, a friend of Ms Oates who saw both her and Mr Wise on the night of his death, failed to appear.

Referring to a medical certificate, Sergeant John Delpero told Coroner Cooper Ms Hosking had phoned, saying she was unfit to give evidence.

However Coroner Cooper denied the claim, saying the certificate did not apply as it was five months old.

He subsequently issued a warrant for her arrest, with Ms Hosking being detained by Police in Huonville later in the day.

Following her arrest, the court was told police were concerned for her welfare, leading to Coroner Cooper not compelling her to give evidence.

Although lawyer Fabiano Cangelosi, who is representing Mr Wise's mother, Faith Tkalac, urged Coroner Cooper to reconsider, saying "there is nothing in the medical certificate that suggests she can't give evidence" whilst suggesting Ms Hosking could give evidence via video link with a support person, she was released without charge.

Amber Lovell was then called to give evidence via video link from the Hobart Police Station.

During her testimony Ms Lovell, who is Ms Oates' cousin, cried, frequently swore and refused to answer questions about if she had lied to police about Mr Wise having previously jumped in front of cars.

"I can't do this, I'm f***ing sick of it," she said at one point.

"It's f***ing bullshit. I'd rather be locked up than have to deal with this shit."

Coroner Cooper then demanded Ms Lovell be removed from the remote witness room to give evidence before him in the witness stand.

Minutes later Ms Lovell appeared in person, where she denied being told by Ms Oates or her friends to talk about Mr Wise jumping in front of cars during her statement to police following his death.

Under cross-examination by Mr Cangelosi, Ms Lovell was asked whether she was attempting to protect Ms Oates.

"No, this has affected me too," she said.

"I don't care about any of this, he's dead, he's not coming back."

The court also heard from Katie Shead, a friend of Mr Wise and Ms Oates who had been socialising with the pair on the night of Mr Wise's death.

Ms Shead testified that a statement she gave to police in 2020 was incorrect, saying she hadn't witnessed Mr Wise jumping in front of Oates' car on a previous occasion and rather that he "jumped back" and that part of the vehicle had "clipped his knee".

Tasmania Police crash investigator Kelly Cordwell, who attended the scene on Huonville's Wilmot Road shortly before 3am, also gave evidence.

Senior Constable Cordwell told the court it appeared Mr Wise has been standing on the road's southbound lane with his body "almost, if not totally, front-on" to to Ms Oates' car.

She said Mr Wise's body would have contacted the windscreen on the passenger side of the vehicle and likely became airborne, with there no evidence of Mr Oates swerving or braking prior to, at the point of impact or afterwards

"The debris indicates the vehicle has continued, with the debris continuing to fall off the vehicle," Senior Constable Cordwell said.

Mr Wise's body travelled some 34 metres after being impacted by Ms Oates' vehicle, with forensic pathologist Donald Ritchie, who performed the autopsy on Mr Wise's body said his death would have been "near-instantaneous".

The inquest continues on Wednesday.