They had already decided they would call their baby Tyler if it was a boy.

It was a dream come true for father-to-be Nick Bridger, a young man who was himself part of a large and close-knit family and wanted children.

When Nick and his girlfriend Michelle Franco discovered they were going to be parents they were overjoyed.

Michelle was going to make her mum Susan Franco a grandmother for the first time. The couple began planning where they would live when Tyler was born.

They went to the Royal Sussex County Hospital in Brighton when Michelle was 12 weeks into the pregnancy for the first scan.

The baby appeared fit and healthy. Nothing seemed untoward.

Michelle, 19, continued to care for the elderly at the residential home in Hove where she has worked for the past four years with her mother Susan, the deputy manager.

She suffered morning sickness but no other adverse effects.

Nick, 21, who has been a scaffolder for six years, said: "We're young and fit and Michelle never drank or smoked through the pregnancy. I went with her for the first scan. The second one I had to work but we thought everything was all right."

That routine check-up was anything but all right. It was the start of a nightmare.

The scan showed problems with the baby's development. Michelle was told to return the next day. She was devastated.

Finally, the shell-shocked couple were told the baby's chances of survival were negligible.

Michelle's mother Susan said: "He was still their baby. He was and still is very much part of the family even then."

Michelle went to the Royal Sussex where she gave birth and signed a form agreeing Tyler could be sent for a post-mortem.

They both needed to know what went wrong - and what the prognosis was for the future. But it was a decision which turned a family tragedy into a scandal.

Nick said: "I only saw him once. I wanted to see him again when he came back."

The whole family are now devastated by the blunder, which is under investigation.

Michelle and Nick cannot believe that the hospital could make such an unthinkable mistake.

Michelle now carries a copy of a national newspaper report on a mass burial in Liverpool of 50 babies whose bodies were secretly used for medical research.

She is terrified Tyler suffered the same fate. Although both hospitals have categorically denied this, no one will ever be able to prove it to her satisfaction.

Michelle said: "I think he was stolen and because he had such a rare condition they wanted to keep him. I can't trust them."

The trust sent Michelle a letter which she received yesterday. In it, the chief executive apologised for the mistake and promised there would be an investigation.

Nick's parents, Karen and Michael Bridger, from Hangleton, Hove, have been married for 31 years.

They lost their daughter Chloe in 2000 and the loss of their grandson Tyler has brought back memories.

Tyler was to have been buried next to Chloe at Angel's Corner in Bear Road cemetery in Brighton.

Mother-of-five Mrs Bridger, 47, said: "It's absolutely disgusting. I didn't even get to see my grandson.

"There's nothing they can do now to bring Tyler back."

Nick said: "We want to put up a plaque or something on a tree. I want him to rest in peace but it really does hurt. He's always on my mind. We want someone to take responsibility. I don't want it to happen to anyone else."