A father has relived the moment he found his daughter soaked in blood after she was viciously attacked by her partner, who then drove his car into the path of a nurse, killing them both in an explosive fireball. 

Perth man Keith Mitton, 42, savagely attacked his partner Sarah with a kitchen knife in her father's bathroom in Exeter, Tasmania, last Friday.

He fled the scene in the blue Skoda hire car the couple had rented when they arrived together with her two daughters to meet her parents in Tasmania four days earlier. 

He drove into oncoming traffic on West Tamar Highway at Legana, near Launceston, and crashed head-on into the car of mother-of-two Elaine Gee, 39, killing them both.

On Friday, Sarah's father Adrian told the Daily Mail horrifying new details of Mitton's frenzied attack on his daughter, who is in her 40s.

He said he had returned after briefly popping out to find his daughter covered in blood and clutching her face, with no sign of Mitton or the Skoda rental car.

'It's impossible to comprehend,' he said. 'At first I thought he'd just smacked her around a bit. I didn't realise right away that he'd stabbed her.'

He revealed Mitton had grabbed a knife from the kitchen before confronting Sarah in the bathroom and launching his brutal attack. 

He confirmed there were 'significant injuries to her face' after sources close to Sarah told the Daily Mail Mitton had 'hacked at her nose and ear'.

'When I got home, there was blood everywhere, and she was on the phone to triple-0,' he said.

Sarah was rushed to hospital where medics are understood to have found her injuries had miraculously missed vital organs.

Her father was set to see his daughter in hospital in Launceston on Friday and said she has now moved out of ICU onto a general ward as she recovers from the attack.

Sarah and Mitton had been staying at Adrian's home in Exeter, arriving from Western Australia with Sarah's two children on July 21. 

It was previously reported Sarah, who lived in Perth, was trying to escape Mitton after relationship problems, but Adrian said they had planned to make the trip together.

He said their relationship had been going on for 'a bit more than six months' - and was serious enough that she wanted to introduce him to her Tasmanian family.

Adrian had not previously met Mitton, a welder from Lansdale in Perth, and knew very little about him but said there were no warning signs of his deadly rage.

He confirmed Sarah's children were in the home when their mother was stabbed, but said they did not directly witness it. 

'One was in the bedroom, and the other was in the living room,' Sarah's father said. 

Adrian said his granddaughters were holding up well after the traumatising attack and he was also getting through it.

'Kids are pretty resilient,' he added.

A GoFundMe for Sarah was created by family friend and local state MP Jess Greene which has so far raised more than $24,000.

'The community seems to be behind us and behind Sarah,' said her father.

'The GoFundMe has raised quite a lot of money. The family has been well supported by the community.'

Sarah's daughters are now in the care of her sister and brother-in-law, Coby and Adam Gore, in Gravelly Beach. 

'The girls have previously lived in Tasmania with Coby and Adam, so they are returning to people they know, love and trust, and to a home where they have already experienced care, stability and belonging,' said Ms Greene.

'Their nan also lives with the family, providing another familiar and loving source of support.'

Ms Greene said the money raised would go towards supporting the children, including schooling and counselling costs.

'Funds will also be used to assist Sarah with medical, rehabilitation and living expenses as she recovers and begins rebuilding her life,' she said.

Through Ms Greene, the family described their pain over the injuries to Sarah, and also Ms Gee's death, with the two families known to each other prior to the tragedy.

'Two families have been changed forever, children have experienced unimaginable trauma, and the broader community has been left shocked and grieving,' read a statement.

'As a family, we acknowledge the profound loss suffered by the Gee family, as well as Elaine's friends and colleagues. 

'Nothing can lessen their grief, and they remain firmly in our thoughts.'

Ms Gee had worked as a nurse in the region for 20 years and was returning home from Launceston Hospital when Mitton veered his Skoda into her Nissan Navara.

Mitton is said to have had fuel drums in his vehicle as part of his abandoned plan to burn down Adrian's home after attacking Sarah.

Mitton was killed instantly in the massive fireball, which could be seen for kilometres.

Ms Gee was rushed to hospital where doctors battled to save her, but police confirmed her death on Sunday. 

'Elaine spent two days fighting for her life in hospital but tragically her injuries were too severe and the family had to say their final goodbyes,' said Lisa Gibson, a friend of the Gees.

Ms Gee leaves behind husband Rodney, who was her high school sweetheart, and two sons aged six and ten.

'There are no clever words for it,' said Mr Gee.

'The entire situation is completely unacceptable... and this is without question the worst day of our family's lives.'

A GoFundMe for Ms Gee's family has raised $223,000, including one anonymous donation of $10,000.

Her funeral will be held on August 7 at the Tailrace Centre in Riverside, north of Launceston and will be livestreamed.

Her family asked mourners to make a blood donation in her honour in lieu of flowers.