A woman at the centre of a legal battle in Ontario over how to define death died Monday morning of natural causes while she was on life-support.

Taquisha McKitty, 27, had an "irreversible cessation of her heartbeat" at 3 a.m. ET, according to Hugh R. Scher, a lawyer who had been representing her family during their court battle to keep her on life-support.

"They're obviously saddened by the loss," Scher told CBC Toronto in a telephone interview. "They're grateful for the public support they've had throughout this year-long ordeal."

McKitty, who had a young daughter, had been on life-support since September 2017, when she went into cardiac arrest following a drug overdose in Brampton, Ont. She was declared neurologically dead by doctors shortly after.

Since then, her family had fought to keep McKitty on a mechanical ventilator, arguing she had shown signs of life and her Christian fundamentalist beliefs said she was alive as long as her heart was beating.

But in June, the Ontario Superior Court of Justice ruled McKitty could be considered dead and that she be removed from life-support.

Unlike four other provinces, including Manitoba and Nova Scotia, Ontario does not have a statutory definition of death, the court decision noted. Instead, death in Ontario is determined by physicians in accordance with accepted medical practice.

"There is no legislation that requires physicians to consider an individual's views, wishes or religious beliefs as factors to be considered in the determination of death," Judge Lucille Shaw wrote in her decision.

After that ruling came down, Stanley Stewart, McKitty's father, told reporters his family was disappointed with the decision because it ignored the young woman's "ongoing biological functions," including a strong heartbeat, as well as the ability to heal from injuries and shed tears.

"If you touch her, she still moves," Stewart said. "As far as our family's concerned, she's never stopped being alive."

However, Shaw's decision noted doctors have found "uncontroverted medical evidence" that there was no blood flow to McKitty's brain and that it would not be able to recover.

The movements, the decision noted, originated in the spinal cord and "do not involve any brain activity." That was proven by a series of medical tests, Shaw wrote.

Family considering brain autopsy

Earlier this month, McKitty's family argued their case at the Ontario Court of Appeal.

At that time, Scher argued that Shaw erred in not recognizing McKitty's charter rights and by not taking into account her religious beliefs. A decision was expected in the new year.

Scher said Monday the family still hopes a court decision will come down that will "clarify the legal definition of death in Ontario" and allow for religious beliefs to be "respected" as part of the process to determine death.

"They would love to see a court ruling that ultimately resolves this issue so that other families are not required to go through the same process," he said.

Scher aims to "seek direction" from the court if further submissions from the family are warranted in the wake of McKitty's death.

Bishop Wendell Brereton, of the Glorious Church Breakthrough Temple, where the family worships, said Monday the family will decide whether to request an autopsy of McKitty's brain to verify if it was damaged in the way doctors indicated it had been.

"This is their closure," Brereton told CBC Toronto. "And it will allow them to know very clearly that they were not fighting in vain."