The sad story of the couple found dead in the swimming pool reminded me of one case which forensic science failed to solve.

This concerned New Zealand-born Rhodes scholar and scientist Gilbert Stanley Bogle, who was found dead along with his companion, Margaret Chandler, at around 8am on 1 January 1963 in Lane Cove, River Park, Sydney.

Both married, they had been to a New Year’s Eve party in Chatswood and left together. When found, Bogle was wearing a shirt and tie, shoes and socks, and was covered with a piece of dirty carpet. Chandler’s button-down dress was open and she was naked from the waist down. She had been covered with a cardboard beer carton.

The pair had been poisoned, but the toxin has never been identified. Suggestions included LSD (traces were found in their bodies), arecoline hydrobromide (used for worming dogs) and yohimbine (a herbal Viagra). Theories ranged from an accident, to taking a drug as a sex aid, to suicide, to poisoning by Chandler’s husband Geoffrey (a rumour he has always denied, writing a book, So You Think I Did It? to dispel it) or Bogle’s jealous ex-lover Margaret Fowler. Other suggestions have included FBI involvement and an attempt to stop Bogle inquiring too deeply into the death of scientist Dr Clifford Dalton.

In her book Without Hardware, Dalton’s wife claimed her husband had been killed by the Australian Security Intelligence Organisation spraying nerve gas in his face. Margaret Fowler left Australia immediately after the inquest and died in London in 1977. Geoffrey Chandler wrote his own account of the case later. Bogle’s FBI file remains classified.

In 2006, a new suggestion by filmmaker Peter Butt in the documentary Who Killed Dr Bogle & Mrs Chandler? was that the couple’s deaths were due to hydrogen sulfide: a gas from a polluted riverbed caused by waste dumped there by a local factory. At first, the pair would have smelt and seen nothing, and by the time they did their respiratory systems would have already been shutting down, as the gas binds reduces blood’s ability to carry oxygen.

As for the covering of the bodies, it was suggested that a local greyhound trainer exercising his dogs had come across the bodies first by accident and covered them for modesty’s sake.

James Morton is a writer and former criminal defence solicitor