The serial killer Stephen Port’s former drug dealer has been jailed for at least 31 years for the “wicked and callous” murder of a former Bond film actor.

Gerald Matovu, 26, met Eric Michels, 54, via gay dating app Grindr in August last year. He gave him a fatal dose of GHB at his home in Chessington, Surrey and then made off with his bank card details and other belongings.

Michels, who had an uncredited role in Skyfall, was found dead in bed by his 14-year-old daughter. He was one of 12 men targeted by Matovu and his lover, Brandon Dunbar, 24, over a 19-month period, jurors heard.

Following an Old Bailey trial, Matovu was found guilty of Michels’s murder and 38 other offences, while Dunbar was convicted of 23 offences.

Jurors were not told about Matovu’s past connection with former chef Port, 44, from Barking, east London, who had also targeted victims through Grindr and killed four of them with GHB overdoses.

Matovu was jailed for life with a minimum term of 31 years by judge Anne Molyneux QC.

Co-defendant Dunbar was sentenced to 18 years in jail with five on extended licence for his role in the “calculated” scheme to drug and steal from men they met through Grindr.

The judge told the pair: “All were victims of your total lack of respect and callous behaviour. You calculated they would be too embarrassed to report the full extent of what happened to them. They showed dignity and courage in giving evidence in the trial.”

She told Matovu: “You had already rendered five men unconscious using GHB. You were an experienced poisoner and were aware of the dangers of the drug.

“You knew as far back as 2015 that it could be used to take advantage of others. You knew it could be life-threatening. You are a highly dangerous predator.”

Eric Michels. Photograph: Metropolitan police/PA

Earlier, Michels’s ex-wife, Diane Michels, said losing him was “the worst kind of nightmare”, and left her to bring up their three children.

Reading a statement in court, she said: “My view of the world has changed. I was always a glass half-full type of person. Now I view people with distrust and am wary of my ability to judge others accurately.

“This has been exacerbated by the callous disregard for Eric’s life that has been displayed in court by the defendants. I never imagined people could be so wicked, and my fear and anxiety for the safety of those I care for is now unimaginable.”

Son Josh Michels, 24, said the impact of losing his father was “unreal”. He said: “I live in regret that I didn’t see my dad every single minute of every single day.

“We will do him proud, as he always used to tell us.”

Sam Michels, 21, was living with his father and was at home the night he was killed.

On Matovu’s lack of remorse, he said that hearing the defendant accuse his father of rape as part of his defence in court was “soul-destroying”.

He said: “You have taken away all the lessons my dad had yet to teach me and all the experiences he deserved as a father – like meeting his grandchildren and walking his daughter down the aisle.

“To me, my dad had the answers to everything and was always the first person I would go to for advice.

“He was everything to me and I’m completely and utterly lost without him.”

Michels’s 15-year-old daughter, who found his body, said: “At 14 I never expected to walk into my own father’s house and find him lying dead in his bed. I would never want anyone to experience that.

“My dad was my best friend as well as my father. I could literally talk to him about anything, so it’s really hard to accept that I have lost both.”

Mitigating, Louise Sweet QC said Matovu was “truly sorry” for the death of Michels and wished to “turn the clock back”.

Matovu had a troubled upbringing and had sought help with gender realignment, having identified as female since the age of eight, the court heard.

Matovu, of Southwark, south London, was convicted of six counts of administering a noxious substance, seven thefts, six counts of having articles for fraud, murder, assault by penetration, assault occasioning actual bodily harm and possessing GBL drugs.

Dunbar, of Forest Gate, east London, was found guilty of three counts of administering a noxious substance, five thefts, six counts of having articles for fraud, two frauds, assault by penetration, assault occasioning actual bodily harm, and dishonestly retaining wrongful credit.