An inquest into the death of a Penryn man who died with three to four times the safe level of paracetamol in his body has recorded an open verdict.

The assistant coroner, Barry van den Berg, heard that Richard James Woodland, aged 50, died aboard the boat on which he lived, the Penryn based Milko, on October 11 2013.

The pathologist, Dr Rolf Hohle, said that after he found “no major factors” which would explain Mr Woodland’s death, he sent a blood sample for analysis. The results showed no drugs or alcohol except for paracetamol, but that the levels of the painkiller were 137 milligrams per litre, when a high risk treatment dose would only result in a reading of 40 milligrams.

When told that Mr Woodland had suffered with a bad leg which caused him a lot of pain, and asked whether he might have taken too much of the drug over a period of time, Dr Hohle said it “would have to be one large dose, taken just before he died.”

Mr Woodland’s sister, Joanne, told the inquest: “I think he was the sort of person who wouldn’t realise taking too much was dangerous. He wouldn’t have read about the dangers of taking too much paracetamol.”

Detective Constable Colin Wheeler said that when police officers arrived at the boat there had been no evidence of a large amount of paracetamol, or of any alcohol, or any medication except for Rennies – an over-the-counter idigestion tablet.

He added: There was no mention of a suicide note or of anything taken deliberately.”

Mr van den Berg recorded an open verdict with the cause of death being paracetamol overdose. He added: “It’s a bit of a mystery. We will probably never know what happened or how it happened.”