Rex and Olga Law were a close and loving couple who were devoted to their only son, John, say their friends and neighbours from Thames.

A friend of the couple, who did not want to be named, has organised a petition, pleading for clemency for a good man unable to cope with watching his wife lose her mind.

The petition, signed by 79 friends and neighbours, was forwarded to Law's defence counsel, Matthew Bates.

An accompanying letter said that Olga, "who had always been impeccably groomed and immaculate, lost all her control, and her dignity".

"This was devastating and very painful for Rex to see her suffering as he was devoted to her.

"We all know that he would never have done anything to upset or cause her pain, and we pray he'll be treated with the compassion and understanding we feel for him."

The friend told the Weekend Herald: "He was so gentle, you would never think he could harm a fly. I feel quite guilty because none of us really knew he was in such a quandary."

Rex Law did not want his wife put in a rest home or hospital.

"He couldn't drive and he didn't know where to put her - it was sort of a catch-22 situation.

"He really needs a lot of sympathy and support, I think."

The couple had lived in the neighbourhood for almost 40 years.

Both ran successful small retail businesses in Thames and were members of the Thames Business Association.

Rex Law was a Rotarian and both were active in the National Party.

About six years ago, Olga's Alzheimer's disease began to show, steadily worsening until she was unable to look after herself.

Another neighbour said the couple were friendly and kind, but did not want to burden others with their problems.

Rex Law was clearly struggling to cope, but would not accept help.

"They were proud and independent and in control of their lives."