A woman suffering from lung cancer, who has just six months to live, has revealed how two empty oxygen cylinders were delivered to her house.

The two bottles were discovered in a batch of five arriving at the home of Vera Lawson in Broomhill Avenue, Keighley, over a six-day period.

Widow Mrs Lawson was diagnosed with lung cancer only days before at Airedale General Hospital, Steeton. She needs the oxygen - plus a cocktail of other drugs - to help her breath.

"It was traumatic enough to be told I had just six months to live - I don't want to die because I haven't enough oxygen," said Mrs Lawson, who needs to use a new cylinder every two or three days. She is not strong enough to re-connect the bottles and relies on her 36-year-old son Peter, of Greystones Mount, Keighley, and his girlfriend Yvonne Shepherd to help her.

Peter, a furniture maker, said the first empty bottle was discovered on Tuesday, August 12.

"It was only luck that made me first open the empty one of the last two. If I'd opened the full one, we would have been left with the empty one and no back-up," he said.

He telephoned the suppliers BOC to alert them and was told to inform the local chemist from where it was delivered and it would be replaced.

A fresh bottle was delivered the next morning followed by a batch of three later in the day.

"We didn't check them because we thought it would be the last thing in the world to find another empty one," said Mrs Lawson, who stressed she attaches no blame to the chemist. "But when I needed the second cylinder on Sunday Peter was amazed to find that was empty. That works out at a 40 per cent mistake rate. If that's the percentage throughout the country it relates to thousands."

She added: "I think they should check their quality control."

A spokesman for BOC said: "This situation concerns us and we will hold a thorough investigation."

The company delivered hundreds of thousands of cylinders and it was not possible to comment further until the complaint was looked into.