A man wearing an electronic tag could have been dead for three weeks before his body was found, an inquest heard.
Robert Little, 25, was wearing an ankle tag when he was found dead at his home in Mowbray Street, Ashton-Under-Lyne, earlier this year.
Stockport Coroner John Pollard returned an open verdict on Mr Little.
Mr Pollard said he would be writing to the Ministry of Justice recommending a more pro-active system of monitoring offenders wearing tags.
Toxicologists found strong doses of pharmaceutical drugs in Mr Little's body at the time of his death.
He was found with a number of the same drugs scattered around him, and a note to his mother by his side.
Stockport Coroner's court heard that Mr Little could have been dead for at least three weeks as when police found him his body was showing significant signs of decay.
Zoe Haslam, a woman who went on a few dates with Mr Little, said she had not heard from him since the middle of January.
Claire Sims, Director of G4S electronic tagging, said that the device would be able to tell if he left home.
Mr Pollard concluded that the monitoring carried out on Mr Little had been "insufficient".
He added that the case had shown the authorities had a "moral duty" to investigate immediately if contact could not be made with people wearing tags.