A former nurse from the US state of Texas who is currently serving time in prison for killing one baby and sickening another in the 1980s is thought by authorities to have possibly killed as many as 60 young children.

Genene Jones, 66, a nurse who worked at hospitals across Texas in the 1980s, is serving a 99-year prison term for giving a 15-month-old girl a lethal dose of muscle relaxant in 1982, and a concurrent 60-year term for administering a potentially lethal injection of a blood thinner to a 4-week-old baby boy who survived.

She was due to be freed next March under a mandatory release law that was in place when she was convicted. However, she was additionally charged on Thursday with administering a lethal injection of an anti-epileptic drug to an 11-month-old boy in 1981.

During the time Jones was working in hospitals, a number of children died of unexplained seizures and other complications.

At a news conference, Bexar County District Attorney Nico LaHood said investigators believe Jones may have killed some or all of those children because they died during or shortly after her shifts under unusual circumstances.

'Pure evil'

Jones may finish her life behind bars

"She's been suspected in dozens of infant deaths and she's only been held accountable in one," said LaHood about Jones, describing her as "pure evil."

If Jones is convicted on all counts, she may be sentenced to up to 99 further years in prison.

"We will do our best to ensure that Genene Jones takes her very last breath behind bars," said LaHood.

Not an isolated case

Jones is far from being the only person working in the nursing profession to be suspected or found guilty of murdering those he or she was supposed to be taking care of.

German nurse Niels H. was sentenced to life in prison in 2015 after being found guilty of murdering two patients. However, a psychologist said the man confessed to killing 30 patients during the trial.

A nurse in Ontario, Canada, was charged with eight murders in October 2016. Police have yet to find a motive for the killings.

kbd/kl (AFP, AP)