The Scottish Prison Service have confirmed that serial killer Angus Sinclair died overnight at HMP Glenochil in Alloa, Clackmannanshire.
Sinclair had been in prison since 1982 after being convicted of a series of rapes and indecent attacks on children.
Whilst in prison he was given a life sentence for the murder of Glasgow teenager Mary Gallacher in 1978.
Five years ago he was convicted of the murders of Helen Scott and Christine Eadie, who were last seen at the World’s End pub on Edinburgh’s Royal Mile in 1977.
He had previously been acquitted of the crimes after his defence lawyer argued that no evidence had been presented proving that any sexual encounter was non-consensual.
The judge agreed and ruled that there was no case to answer.
Following the introduction of the Double Jeopardy (Scotland) Act he was retried and convicted. He was sentenced to a minimum of 37 years in prison.
Sinclair grew up in the St George’s Cross area of Glasgow and age 16 killed his seven-year old neighbour Catherine Reehill, serving just six years.