Louis Mallia has been jailed for three years, after being found guilty of supplying a near fatal heroin dose to a drug user 15 years ago.
The 47-year old had supplied heroin to a first time-user, who was taken to hospital after falling unconscious.
Police launched investigations when Mr Bonavia, the heroin user, entered the Emergency Ward following the overdose.
He was found unconscious in Valletta around Christmas and doctors noticed needle marks on his forearm.
Mr Bonavia, during his testimony, said that he told Louis Mallia that he had never taken heroin before and was assured that it would be ok.
He testified that the two bought heroin from someone called Grezzju Camilleri in Valletta, and Mr Mallia administered the drug. He then woke up in the intensive care ward.
In his version of events, Mr Mallia testified that he had collected a cheque for Lm22. In the afternoon, he left the flat and found Mr Bonavia snoring upon his return.
Magistrate Miriam Hayman found that evidence pointed towards Mr Mallia supplying and administering the dose of heroin.
Mr Mallia was also fined €5,000.
Police Assistant Commissioner Stephen Gatt prosecuted.