The case marks the first time defendants have been convicted under the Modern Slavery Act of an organ harvesting conspiracy. Though it is lawful to donate a kidney, it becomes criminal if money or another material advantage is rewarded.
A Nigerian senator, his wife and a medical "middleman" have been found guilty of conspiring to traffic a market trader to the UK to harvest his kidney.
Politician Ike Ekweremadu, 60, his wife Beatrice, 56, and 25-year-old daughter Sonia stood trial accused of a conspiracy to bring the man to Britain from Lagos for his body part.
It was alleged that the 21-year-old street trader was to be rewarded for donating the organ to Sonia Ekweremadu, in an £80,000 private procedure at London's Royal Free Hospital.
Dr Obinna Obeta, 50, the medical "middleman", was found guilty.
The Ekweremadus' daughter Sonia, 25, who has a serious kidney condition, wept as she was cleared of the same charge.
The case marks the first time defendants have been convicted under the Modern Slavery Act of an organ harvesting conspiracy.
Though it is lawful to donate a kidney, it becomes criminal if money or another material advantage is rewarded.
The prosecution claimed the donor was offered up to £7,000 along with the promise of a better life in the UK.
The donor did not understand until his first appointment with a consultant at the hospital that he was there for a kidney transplant, the Old Bailey heard.
He was said by the consultant to have a "limited understanding" of why he was there and was "visibly relieved" at being told the operation would not go ahead.
It was claimed the man was falsely presented as Sonia's cousin in a failed bid to persuade medics to carry out the procedure at the Royal Free Hospital.
The donor cannot be identified for legal reasons.
The Ekweremadus, who have an address in Willesden Green, northwest London, and Dr Obeta, from Southwark, south London, denied the charge against them.
Detective Superintendent Andy Furphy praised the survivor's bravery and urged people to look out for other victims of modern slavery, which he said is "all around us".
Prosecutor Joanne Jakymec called it a "horrific plot" and said the defendants "showed utter disregard for the victim's welfare, health and wellbeing".
Victim walked into police station cryingThe court heard that Dr Peter Dupont, a consultant at the Royal Free Hospital, concluded the donor was not an appropriate candidate after learning he had no counselling or advice about the risks of surgery and also lacked funds for the lifelong care he would need.
Undeterred, a "corrupt interpreter" was allegedly enlisted for £1,500 to help at the donor's second hospital meeting with a surgeon.
An investigation was subsequently launched after the young man ran away from London and slept rough for days before walking into a police station more than 20 miles away in Staines, Surrey, crying and in distress.