The mother of a woman who was dying from CJD was asked by disease investigators whether her daughter ate pet food and grass.

Patricia Greaves, 46, from Rochdale, Greater Manchester, died just days after being interviewed by a team from the UK's CJD Surveillance Unit.

Her husband Kevin said a researcher from the unit visited her mother's home, where she was staying.

The Department of Health (DOH) has confirmed the unit asks "standard" questions about whether a victim has eaten pet food but not whether they ate grass.

I've never seen anyone sit down and eat a bowl of grass, I couldn't believe it

Kevin Greaves

Mr Greaves, 53, told BBC News Online he was publicising his wife's case to try to force the government to say exactly what causes the disease.

His wife's mother Margaret was asked the questions.

He said: "The first question was about whether Tricia had eaten pet food.

"Margaret said 'You can't be serious?'. But the woman said some people are known to eat it.

"She then asked whether Tricia had eaten liver, kidney and tripe, which was reasonable.

"But then she finished up with 'Has she ever eaten grass?' - now I've never seen anyone sit down and eat a bowl of grass, I couldn't believe it."

Mr Greaves said tests carried out did not reveal which one of the four strains of CJD had killed his wife, though the most likely was the sporadic form and not the variant strain that is caused by BSE.

A DOH spokeswoman said the questions Mrs Greaves' mother was asked were simply designed to "investigate every possible cause of what is a terrible disease".

She said: "They do not include anything about grass, but do include questions about pet food.

"The questionnaire has been developed over the last 12 years and was considered by the BSE inquiry.

"We are grateful to relatives and victims for working with the investigators."