Eminent plant scientist David Lloyd, who was left comatose, blind and severely paralysed after allegedly being poisoned by his former lover, died yesterday. He was 68.

Fellow Christchurch scientist Vicky Calder was cleared of attempting to murder him after police spent more than $1.5 million over two trials trying to prove that she poisoned him with acrylamide monomer.

Professor Lloyd, then in his mid-50s, was struck down by a mystery illness in late 1992 after he broke up with Dr Calder and married Canadian plant researcher Linda Newstrom.

The twin trials filled newspapers and television screens with their claims of a scorned woman accused of trying to murder her former lover with a mystery poison.

Dr Calder, a molecular biologist, was arrested in June 1994 and charged with attempted murder or, alternatively, poisoning with intent.

The first trial ended in a hung jury. The jury in the second trial acquitted her.

When Professor Lloyd collapsed in 1992 he was in a coma for more than three months and left blind with severe, unusual and complicated nerve damage.

He was at the height of his teaching and research career and widely acclaimed for his pioneering work on the theory of plant reproduction.

That year he became just the seventh New Zealander to be elected a Fellow of the Royal Society, London.

The professor, a popular teacher, had separated from his wife and was living with Dr Calder, whom he had met in 1986.

By 1992 she was working as a molecular biologist at the Christchurch Medical School. But their de facto relationship foundered after Professor Lloyd fell in love with Ms Newstrom.

Dr Calder took the end of the relationship badly.

Mrs Newstrom-Lloyd was quoted last night as saying her husband had lived the past 13 years with "cheerfulness and resiliency".

"In spite of his difficulties as a result of his injuries, he always made the most of what he had."

Dr Calder, now Vicky Webb, joined the National Institute for Water and Atmospheric Research in Wellington in 1998 and is the leader of several science programmes.