A British businessman serving a sentence for two murders has been framed and the killings were carried out by executioners working for Pablo Escobar's notorious Medellin cartel, it has been claimed.

Jhon Jairo Velasquez Vasquez - Escobar's chief assassin responsible for the killing of 300 people - has sensationally stated 75-year-old Kris Maharaj has been wrongly imprisoned just as lawyers battle to overturn his conviction.

Maharaj was working in Miami, Florida, as a property investor in 1986 when he was convicted for the murder of father and son Derrick and Duane Moo Young at a downtown Miami hotel.

Escobar's assassin, Jhon Jairo Velasquez Vasquez (pictured), has claimed British businessman Kris Maharaj was framed and the double killing was the work of hitmen working for the Medellin cartel

Maharaj, now 75, has spent almost three decades in a Florida prison for a crime he says he did not commit. Here he is pictured during this week's court hearing which his legal team hope will overturn his conviction

His legal team has been battling to have the conviction overturned in recent years with new evidence alleging the murders were carried out by hitmen working for Colombian drug lord Pablo Escobar.

Now Velasquez, the kingpin's most feared assassin who is responsible for killing 300 hundred people, has claimed through his lawyers that Maharaj was wrongly convicted.

Velasquez, who lives in a secret location following his release from prison in August, called a former agent for the US Drug Enforcement Agency to state his claim,The Guardian reported.

Former agent Henry Cuervo said: 'Velasquez said he wanted to clear his conscience, he wanted to say who had killed the Moo Youngs. He said it was Pablo Escobar and his people.'

Velasquez added: 'As a lieutenant of Pablo Escobar Gaviria, with whom I worked shoulder to shoulder, he told me directly that they had stolen his money and that of his partners and that therefore "they had to die",' the paper reported.

Lawyers for Maharaj described the call in a court hearing which concluded this week.

Velasquez (pictured in prison in 2009), was released in August in return for providing information on other murders carried out during the bloody reign of Pablo Escobar

Colombian drug kingpin Pablo Escobar (pictured left on his son's book cover) ordered the deaths of thousands of people during his time at the head of the Medellin cartel. Velasquez is pictured right as a young assassin

Yesterday a Florida judge wrapped up the three-day hearing, which was held to re-examine Maharaj's conviction.

His legal team, led by British civil rights lawyer and activist Clive Stafford Smith, hope to persuade Florida Circuit Court Judge William Thomas to overturn the conviction, saying new evidence indicates the Moo Youngs were money launderers who stole from Escobar's Medellin cartel.

Thomas has not said when he plans to rule, but lawyers said it could take several weeks.

As well as hearing from Mr Cuervo, the court heard testimony from an alleged former Medellin cartel enforcer, Jorge Maya, in a taped Skype interview from Colombia claiming that Escobar ordered the hit.

He said: 'I am 100 percent sure that ... Kris Maharaj had nothing to do with the assassinations.'

Furthermore, a former U.S. government informant, Baruch Vega, said on Wednesday he learned at the time that the killings were arranged by a top cartel boss who had the hotel room across the hall from where the Moo Youngs were slain.

An American pilot who flew cocaine shipments for the cartel also testified that he heard Escobar say he ordered the killing, telling prosecutors: 'You got the wrong guy.'

A lawyer who investigated the Moo Youngs' finances for a life insurance company testified that their business records suggested they were money laundering, although they were depicted as legitimate businessmen in the 1987 trial.

Prosecutors said the defense case consisted entirely of hearsay and unproven allegations. The Moo Youngs' financial records did not change the case 'one iota,' prosecutor Penny Brill said.

The fingerprints of Maharaj, a once wealthy businessman who divided his time between Britain and Florida, were found in the hotel room where the murders took place and he had a long-running feud with Derrick Moo Young, prosecutors said.