'Cancer drug mistake killed my child'

Richie was just 12 when he died

Other cases in which vincristine was injected into the spine - with fatal consequences - have been highlighted by the BBC.

Dolores William's 12-year-old son Richie died within a few days after the blunder at Great Ormond Street Children's Hospital in 1997.

They just broke their own rules and safety procedures, and Richie ended up dead

Dolores William

He was being treated for non-Hodgkin's Lymphoma, a form of cancer, and had been told that earlier chemotherapy sessions had brought him into remission.

Dolores told BBC Watchdog Healthcheck: "I had been told that there was a 75% chance that he would recover, and he had done it.

"We were going for two injections, vincristine and methotrexate - one into the spine, and one into a vein.

Dolores William: "It will happen again"

"It hurt him - it hurt him straightaway. There was pain straightaway."

At this point the doctor, noticing his discomfort, stopped the injection, gave him a five minute break, then finished it.

Thinking Richie had fallen asleep, Dolores went to buy something from the hospital shop, telling nurses to tell him she was there should he wake up.

However, he never regained consciousness and died five days later.

'It will happen again'

Dolores says: "They just broke their own rules and safety procedures, and Richie ended up dead.

Charles Newins was another victim

"I don't believe it won't happen again - I'm sure it will."

Jill Cox's 68-year-old father Charles Newins was also given the toxic drug into the spine.

"After that he just lived for two weeks. There is no antidote to this vincristine. It's death.

"I want so many questions answered. Why did it happen? How did it happen?"