A former longtime senior adviser to Christopher ‘Dudus’ Coke, the Jamaican drug lord who pleaded guilty last year to federal conspiracy charges in Manhattan, has been cooperating with the authorities to help build the criminal case against his former boss, a new court filing shows.

According to a report in the New York Times today, the former adviser, identified only as ‘John Doe’ in the filing, had been a bodyguard and close aide to Coke’s father, Lester Lloyd Coke, popularly called ‘Jim Brown’. His tenure began in the 1980s when ‘Jim Brown’ ran what prosecutors say was the Jamaican criminal organisation that his son, ‘Dudus’ eventually took over.

“Over time, I became, in essence, a trusted senior counselor to the organisation,” the former adviser said in a 26-page statement filed last evening in Federal District Court in Manhattan.

The organisation, called the Shower Posse, was based in Tivoli Gardens, and it became involved in murder, extortion, armed robbery, and narcotics and firearms trafficking, the former adviser wrote.

Dudus was extradited in June 2010 after a month-long manhunt in Jamaica that left more than 70 people dead. When he pleaded guilty last August, he admitted he had led the organisation, which he said had distributed crack cocaine and other drugs in Jamaica and the United States, including in the Bronx.

The government’s disclosure that it had obtained the cooperation of two insider witnesses came on the eve of a court hearing today at which prosecutors are expected to present their case that Coke, 43, should receive the maximum sentence possible, 23 years.

Coke has written to the judge, asking for leniency; and his lawyers have made it clear in court papers that they planned to attack the government’s depiction of their client, as they put it, ‘as a murderous scoundrel, whose evil knows no bounds’.

The judge, Robert P Patterson Jr, called the hearing after prosecutors said they wanted to introduce evidence against Coke that went beyond the crimes for which he was convicted. Coke, for example, admitted in his plea to conspiring in a single assault, of one man who owed a drug debt.

The prosecution plans said it did plan to call another former high-level member of Coke’s organisation, who it said was also cooperating.

‘That witness is expected to describe, among other things, brutal murders, beatings and other acts of violence that were committed by Coke or at his direction,’ prosecutors wrote. This witness is not named in the filing, but would presumably be identified after taking the stand.

This witness, prosecutors said, would also detail how Coke armed his crew of loyal “soldiers” which sometimes numbered more than 200, with guns that he illegally imported from the United States, and how he used women from Tivoli Gardens to smuggle cocaine into the United States.

It is the former counsellor to Coke, though, who appears to have had the longest and closest relationship to the defendant, who took over his father’s criminal network in the early 1990s, prosecutors said.

In 1992, for example, Coke told the adviser that he needed to obtain more high-powered weapons in order to have more power, both within the group and in Jamaica.

‘The older members of the organisation needed to understand that he would be running the organisation now,’ the witness wrote.

The witness said Coke’s crew included teenagers as young as 14, who ran errands or acted as lookouts until they were old enough to be given weapons. The witness also described Coke’s brutal code of discipline, and how he once ordered his men to shoot as many people as possible on a street associated with a suspected informer.

‘I later learned that four or five people were shot, including two women,’ the witness wrote.

In smuggling arms into Jamaica from the United States, Coke’s group packaged firearms inside refrigerators and other appliances, and handguns and ammunition inside food shipments, like rice and flour, the witness said.

The witness admitted in his statement that he had been involved in cocaine trafficking for more than a decade, and that at times he had lied to the American authorities. He said he eventually pleaded guilty to conspiracy, and received a long prison term.

The witness said he hoped that his cooperation would lead to his being given a new sentence of time served.