Christine Lord believes 24-year-old son Andy contracted variant Creut-zfelt-Jakob disease before 1994.

However he showed no symptoms until the end of 2006 and was initially told he was depressed – a common misdiagnosis according to experts.

By the time the disease was detected last July he was unable to walk properly, had memory problems and struggled to carry out simple tasks. He died last December.

Now Christine, from Southsea, has started a crusade in memory of Andy and more than 200 other victims of variant CJD in the UK.

She has launched a campaign website and is urging readers to sign up online in support.

The freelance journalist stopped giving her two children beef when Andy was about six after concerns over links between eating the meat and CJD were at their peak.

Daughter Emma, 18, has shown no sign of infection.

Christine said: 'The problem with CJD is that it can take hold very gradually. By the time he was diagnosed it was too late.

'Andy had a wonderful career ahead of him. He was a gentleman and a wonderful man who didn't like any sort of injustice. His death was avoidable.'

It is not known how Andy contracted the brain bug.

But Christine believes the government could have done more to prevent people from dying from the disease.

'People need to know there are people who are still in (positions of authority] in this country who I believe have contributed to the deaths of nearly 200 people from VCJD,' she said.

Christine's story will be aired on Inside Out on BBC1 at 7.30pm.