A Serb gangster in Spain was arrested after he attempted to buy a poor immigrant's kidney for 6,000 euros ($6,835) and threatened to kill him if he pulled out of the deal, police said Monday.
The gangster, head of a clan based around the sunny beaches near Tarragona in northeastern Spain, wanted the organ for his grown-up son who had kidney disease.
The plan came to light during a wider probe into a Serbian clan accused of burglaries in Spain and Germany, the chief of the Spanish police Ignacio Cosido told a news conference.
While investigating the burglary racket, officers found the gang had persuaded an undocumented middle-aged Moroccan immigrant to donate his kidney.
After undergoing medical tests, "he changed his mind, so the group detained him and beat him," Cosido said.
The immigrant agreed to go ahead with the operation after the gang threatened to kill him.
Spanish police arrested the gang boss and his son and three other people for the alleged kidney-trafficking deal.
Spanish police also detained a further 48 people over the alleged burglaries. They are accused of recruiting children to break into rich people's homes and steal jewellery and cash.
In Spain in March, 14 European nations signed the first ever international treaty to fight human organ trafficking.
The business generates 1.2 billion dollars in illegal profits worldwide every year, according to the Council of Europe, which drew up the treaty.
The World Health Organization estimates some 10,000 black market transplants are carried out worldwide every year.
It was only the second reported case of attempted organ-trafficking in Spain in recent years.
But authorities took the case seriously in a country that boasts of carrying out more transplants than any other country.
"No country is free of this (organ-trafficking) phenomenon and we must all be on our guard," said the head of the state National Transplant Organisation, Rafael Matasanz, on Monday.