The convictions, delivered in the Kingston Crown Court Monday evening, came after what is called the biggest counterfeit drugs bust in British history. The investigations were led by the Medicines and Healthcare products Regulatory Agency (MHRA).
The men were charged with masterminding the industrial-scale supply of counterfeit medicine between 2002 and 2005, involving millions of pounds worth of counterfeit Viagra, Cialis and Propecia.
The medicines contained around 90 percent of the normal active ingredient found in the authentic tablets - but regulators said customers were put in danger because of other possible ingredients.
These seizures resulted in the MHRA unravelling the biggest conspiracy of the supply of counterfeit medicines thus far in Britain. Over 1,500,000 pounds of counterfeit medicines seized were intended to be supplied to customers through this conspiracy.
MHRA sources said that in the autumn of 2002, revenue and customs officials seized counterfeit Viagra at Stansted airport. This was followed by a number of other seizures at Stansted and Heathrow airports where false descriptions like "Vitamins C and E", "Calcium for Kids" and "Samples of Mineral Supplements for Dogs" were used for a variety of products.
The counterfeit medicines were filtered for sale through licensed wholesalers to pharmacies in Britain and through Internet sites operating both in Britain and overseas. In 2004, counterfeit Cialis made its way into the regulated supply chain reaching patient level. This led to a recall of that product from the British market.
The chance interception of a packet containing 12,000 fake Viagra tablets led to the arrests. The packet was addressed to Leicester-based Gary Haywood, 58, who claimed to be working for drugs firm Pfizer. He told undercover investigators on camera that "within 6-8 weeks I will be able to supply up to a million tablets".
Haywood, along with Ashwin Patel, 24, of north London, and Zahid Mirza, 45, of Ilford, Essex, were found guilty last month of a number of counts of conspiring to sell fake medicines.
Ashish Halai, 31, of Borehamwood, Essex, described as the British "lynchpin" of the operation, had already pleaded guilty to four counts of conspiring to sell the fake drugs before the trial started almost nine months ago. He was jailed for four-and-a-half years.
The jury failed to reach verdicts on four other defendants. George Patino, a doctor from Mexico, Alpesh Patel, a pharmaceutical sales representative from Kingsbury, London, pharmacist Rajendra Shah of St. Albans, Hertfordshire, and businessman Ketan Mehta of Grove Park, London, will face a retrial next year.
Judge Nicholas Price said: "Greed is the over-riding motivation for such an offence." He added that it was "an undeniably lucrative business" where consumers were "easy prey, often too embarrassed to seek help from their doctors".
Sarah Jarvis from the Royal College of General Practitioners said: "It is highly likely that the people who buy these drugs online would not dream of going out into the back streets of India and eating off the floor their lunch from a street cafe, and yet that's effectively what they're doing."
The investigation traced a complex network of individuals, companies and bank accounts facilitating the movement of these medicines. Over a period of time, the men conspired together with the common purpose to profit from these counterfeits.
The men were part of the British distribution arm of a global counterfeiting ring, operating from China, India and Pakistan, and extending to the Caribbean and the US.
Mick Deats, Head of Enforcement at the MHRA said: "The MHRA treats every report of a counterfeit medicine as a serious incident. We will continue to use every power at our disposal to prosecute those engaged in this illicit activity and confiscate the proceeds of their crimes.
"This successful prosecution should serve as a clear signal to those contemplating the supply of counterfeit medicines. The public are strongly advised to avoid buying medicines online, where the risk of being provided with counterfeit medicines is greatly increased."
The verdicts could only be reported on Monday after restrictions were lifted by the court. The MHRA is the government agency responsible for ensuring that medicines and medical devices work.