LONDON (AFP) - A British chef was found guilty on Wednesday (Nov 23) of murdering three men he met on gay networking sites after plying them with a date-rape drug.

Stephen Port, 41, invited the men back to his flat and spiked their drinks or injected them with the drug GHB so he could have sex with them while they were unconscious, London's Old Bailey criminal court heard.

He dumped their bodies in or near a graveyard close to his home in Barking, east London, planting bottles of the drug on some of them and writing a fake suicide note for another, in an attempt to cover up his crimes.

Port gave no reaction as he was found guilty of the murders of Gabriel Kovari, Daniel Whitworth and Jack Taylor, all in their 20s, as well as a string of rapes and sexual assaults on other men who survived.

He was convicted of a total of 16 offences committed between February 2012 and October 2015, which bore striking similarities.

Jurors have yet to reach verdicts relating to other charges including those around the death of the defendant's first alleged murder victim, Anthony Walgate.

Port denied all of the 29 charges against him.

"In the pursuit of nothing more than his own sexual gratification, (Port) variously drugged, sexually assaulted and in four cases killed young gay men he had invited back to his flat," prosecuting lawyer Jonathan Rees told the court during the trial.

Jurors heard how Port was attracted to smaller, boyish looking men, whom he sought out on social networking sites such as Grindr.

Evidence against him included Internet searches for pornography involving young men being "raped" by older men and home-made videos of him enacting his drug rape fantasy.

He also used the Internet to buy a range of drugs, including poppers, Viagra, Meow Meow - a synthetic stimulant - and GHB and GBL, chemically similar substances which can induce euphoria but can also have strong sedative effects.