In testimony sent to Chilean Judge Claudio Pavez, Manuel Contreras alleges that Pinochet and his son, Marco Antonio, organised a massive production and distribution network in the mid-1980s.
According to Contreras, once the former Chilean dictator's ally and now his bitter enemy, Pinochet ordered the army to build a clandestine cocaine laboratory in Talagante, a town 24 miles outside Santiago. There he had chemists mix cocaine with other chemicals to produce what Contreras described as"black cocaine" capable of being smuggled past drug agents in the US and Europe.
Pinochet denied the charges. His son also denied the charges, and has initiated a libel action against the former head of intelligence whom he called "a liar" and "a monster". "There is a whole family affected, you understand, with this slander and defamation," he told a Santiago court
The details of Contreras's testimony first appeared in Chile's La Nación newspaper. The Pinochet fortune, amassed during the dictator's 1973-1990 rule, is now estimated at $26m and is being investigated in Chile, the US and Europe.
The mastermind behind the cocaine operation, alleges Contreras, was Eugenio Berríos, a renegade chemist used repeatedly by Pinochet's secret police, Dina, to run clandestine laboratory experiments.
Earlier testimony and documents show that Berríos and the lab tested anthrax and botulism, and were able to produce the deadly gas sarin. The drug operation, says Contreras, was designed to raise cash for the dictator.
Contreras is serving two jail terms for human rights violations. As the former director of Dina, he is accused of running death squad operations which led to the murders of an estimated 3,000 Chileans in the mid-1970s.
Details of the cocaine operation came as part of an investigation into the murder of Colonel Gerardo Huber, a senior intelligence operative and close friend of Contreras. Huber was found murdered in the middle of an investigation that implicated the Chilean army in breaking a UN weapons embargo and sending arms to Croatia in 1991. Huber, who was expected to testify before Chilean judges, was kidnapped and his body dumped.
With mounting evidence that Pinochet personally planned the 1992 execution of Huber, ex-allies such as Contreras have turned on Pinochet and now allege a stunning list of crimes and cover-ups.
Chile's president, Michelle Bachelet, called on the courts to carry out further investigations.
While allegations of cocaine sales are new, the alleged use of clandestine arms deals has been under investigation for two years in Chile. Investigators in Chile and Britain continue to look at the role of British Aerospace (now BAE Systems) in a number of payments to Pinochet advisers. Whether those fees were consultant fees or kickbacks is under investigation.
In addition to the investigation for tax fraud and falsifying documents (passports), Pinochet also faces investigation for his role in "Operación Colombo", an organised massacre of dozens of regime opponents by Dina in 1974 and 1975.