Croydon Crown Court heard that paramedics had attended to another man, who cannot be named for legal reasons, several days earlier, who had also been drugged and robbed by Osei.
The pair then used the man’s details to unsuccessfully buy nearly €70,000 worth of diamonds from a jeweller in New York.
Guilty
Both Osei and Cristea were also accused of one count of administering a poison or noxious substance so as to endanger life, two counts of theft and eight counts of fraud.
The jury returned a majority verdict on all counts for both defendants on Friday.
Osei admitted manslaughter but was convicted of murder.
He also pleaded guilty to an alternative charge of administering poison, with intent to injure, aggrieve, or annoy, and seven counts of fraud.
He denied two counts of theft.
Cristea admitted one count of fraud and two counts of handling stolen goods, but was also convicted on all counts.
Prosecutor Crispin Aylett QC told the court the drug scopolamine is known as “Devil’s breath” in Colombia and is said to be “popular with robbers and rapists” to incapacitate their victims.
Heartbroken
Following the verdict, Mr Murphy’s brother, Robert Murphy, paid tribute to the “inspirational Irishman” and said his death had “left a huge void” within the family.
“The world is full of sameness, but this could not be said of our brother Adrian,” he said in a statement.
“Adrian brought the love and art of dance to thousands of young people all over the world.
“He made so many loyal friends who are so sad at his untimely passing as he was an inspirational Irishman, who was a gifted dancer and choreographer.
“He was also very funny and made everyone laugh at his hilarious stories. He had the gift of bringing people together.
“Our family is heartbroken that Adrian is no longer with us.
“He has left a huge void within our family and the fact we can no longer see or hear from him makes his absence felt all the more.
“Adrian loved his hometown of Kilkenny and, although he was a regular world traveller, he never missed an opportunity to return to his family and friends.
“Adrian’s legacy is that of a hero and hopefully his tragic death has stopped this happening to any other innocent victim.
“He is now dancing amongst the stars. May he rest in peace.”
Osei, who was previously living at Kerswell Close in Seven Sisters, north London, and Cristea, of Langley Park, Mill Hill, Barnet, north London, were convicted on all charges.
They are due to be sentenced at the Old Bailey in London on December 14th.