A prolific criminal was found dead at home, just 48 hours after being released from prison.
David Emmanuel Valencia, 70, was released from HMP Altcourse , Fazakerley just two days before he was found dead at his home in North Wales on April 26.
A fatal level of the methadone - which is given to drug addicts as a substitute for heroin - was found in the Rhyl-born Mr Valencia's system, reports North Wales Live.
He also had epilepsy medication and an anti-psychotic drug, in his system.
North west wales coroner Dewi Pritchard Jones said during his inquest in Caernarfon that Mr Valenica was "known for the use of heroin, methadone and alcohol" as well as having various medical conditions.
Valencia had more than 450 offences to his name at the time of his death included drug and alcohol related incidents.
During the inquest Mr Valencia's brother said that he had been a registered heroin user in the past.
Mr Pritchard said: "Unfortunately I have seen several identical deaths to this one.
"Mr Valencia was a known user of drugs - he had been discharged from prison and was found dead 48 hours later having overdosed on methodone of which a large quantity was found in his system.
"All to often those used to taking drugs build up a tolerance and they need to take more and more to achieve the desired effect.
"When he was in prison the availability would have greatly reduced and prison officers would have tried to wean him off the level of drugs he was on meaning his tolerance reduced.
"Mr Valencia on being released went back to his bad old ways and took drugs at the same level as before but had not realised that by going back to his old dosage he was overdosing.
"There is no evidence that he had been in touch with his GP after his release from prison but the types of drugs found in his system are available on the street."
