The report, from the San Francisco medical examiner, said Murdock, 42, had hanged himself using the cord of a vacuum cleaner. The time of his death was put at 9am local time on 29 December.
The news of his death became public last December, coming soon after he wrote a series of disturbing tweets on 28 December, which made it appear that he had been arrested and mistreated by the police.
It now appears that some of his friends who were alarmed by the tweets, called the San Francisco police department and asked them to investigate. An officer who went to Murdock's home found him dead.
Murdock's neighbour told the police that he had been going through a series of problems, having broken up with his girlfriend, and facing eviction from the premises at the end of December.
The report said he had been arrested by police on 26 December on suspicion of being intoxicated, resisting arrest and assaulting a police officer.
Murdock founded Debian in 1993. The project has grown to be one of the most successful open source projects.