The bodies of two seniors were exhumed on Tuesday as part of a police investigation into a former Ontario nurse accused of killing eight patients in her care.

Elizabeth Wettlaufer is also facing four attempted murder charges and two counts of aggravated assault.

Police have alleged the crimes took place over the last decade at three long-term care facilities in Ontario where the 49-year-old Woodstock, Ont., woman worked as a registered nurse, and a private home.

On Tuesday, London police said the bodies of two alleged murder victims -- Arpad Horvath, 75, and Helen Matheson, 95 -- were removed from their graves.

"This was a necessary process that was respectfully carried out," said Const. Sandasha Bough. "It's necessary to allow Ontario forensic pathology service to conduct an autopsy and collect evidence."

Bough said the seniors' bodies were exhumed from separate locations with the blessings of their families.

"They're supportive of the reasons," Bough said, adding that she couldn't speculate on whether other alleged victims' bodies would be exhumed in the future.

Horvath's daughter said she was at the London, Ont., graveyard when police exhumed her father's body.

"I sat in my car through the whole thing and freaked out, crying," said Susan Horvath. "It's very painful. It's like going to the funeral all over again, all over again. And we're exhausted."

Arpad Horvath was staying at a Meadow Park long-term care home in London when he died in 2014. The stress of the police investigation into his death has taken a toll, his daughter said.

"I just hope that with all the trouble that the families who are getting their loved ones exhumed -- what we're going through psychologically and every which way -- I hope that there's light at the end of this tunnel and we do find the reason for their deaths," she said.

Matheson's body was exhumed from a grave near Woodstock, Ont., police said. She was living at the Caressant Care home in Woodstock when she died in 2011.

The police investigation into Wettlaufer began last September after authorities became aware of information Wettlaufer had given to a psychiatric hospital in Toronto that caused them concern, a police source has told The Canadian Press.

In October, Wettlaufer was charged with eight counts of first-degree murder in connection with the deaths of residents at nursing homes in Woodstock and London. In those cases, police alleged Wettlaufer used drugs to kill the seniors while she worked at the facilities between 2007 and 2014.

Earlier this month, she faced six additional charges related to seniors in her care. Court documents allege Wettlaufer injected the six new alleged victims with insulin.

Records from the College of Nurses of Ontario show Wettlaufer was first registered as a nurse in August 1995 but resigned Sept. 30, 2016, and is no longer a registered nurse.

The allegations against Wettlaufer have not been proven in court.

Her case is next in court on Feb. 15.