Unmasked: the Briton accused of supplying drugs to US death row

At first glance, there appears to be nothing out of the ordinary about the small shop front for a driving school, located on a grey industrial strip in Acton, west London.

But after weeks of investigation, the unremarkable offices of Elgone Driving Academy, on Horn Lane, can be exposed as the home of another company, one accused of exporting a cocktail of British-made drugs to the US for use in executions.

The Independent revealed yesterday that the three drugs used in the lethal injection process in Arizona had been shipped to the American state by the small business in London.

An invoice, retrieved from US court documents, reveals that the company facing these allegations is Dream Pharma Limited, run from the Acton property by the man listed in company accounts as its director, Mehdi Alavi. He described his job as "wholesaler".

The invoice indicates that on 28 September 2010, Dream Pharma charged the Arizona Department of Corrections £4,528.25 for the supplies of sodium thiopental, pancuronium bromide and potassium chloride. The chemicals were dispatched to Carson McWilliams, the warden of the Arizona State Prison Complex.

Sodium thiopental is used to render the inmate unconscious. Pancuronium bromide is then administered to cause paralysis of the respiratory muscles. Potassium chloride is then given in a high dose to stop the heart, causing a massive heart attack. (Supply of these drugs was not illegal at the time.)

Confronted by The Independent yesterday, Mr Alavi, 50, said he did not wish to comment about any of the allegations he faced. "It does not matter what I do, I am not even going to comment on anything," he said. When presented with the Dream Pharma invoice, he declined to comment on whether he had supplied the drugs.

Just a short drive from the grounds of Hampton Court Palace, the curtains were drawn at Mr Alavi's large home in the leafy village of Hampton, in Richmond-upon-Thames. Neighbours were unaware of the nature of Mr Alavi's business interests. One said the entrepreneur was friendly but private.

The latest accounts for Dream Pharma Limited, filed in January 2010, show it had an annual turnover of £844,229. Mr Alavi was listed as the director and main shareholder. It made a net profit of around £95,000 during the year.

US states have had to look abroad for supplies of the drugs because domestic manufacturers have been unable to source the necessary raw materials. This combination of drugs has already been used to kill one prisoner in the state: Jeffrey Landrigan, a convicted murderer, was put to death in October.

Emails secured under the Freedom of Information Act also show that Arizona agreed to supply its neighbouring state, California, with the same drugs. Some British nationals are facing the death penalty in California. Dream Pharma is not thought to have made the drugs. Instead, it is alleged that it acted as a middle man by purchasing them from British manufacturers and selling them on to the US. The only British supplier of sodium thiopental, the Reading-based Archimedes Pharma, has always denied shipping the drug to US states.

The Independent has learnt that potassium chloride supplied to Arizona under the Dream Pharma invoice originated from Hameln pharmaceuticals, based in Gloucester. The firm immediately contacted all its suppliers when it learnt its product, designed to help patients with a potassium deficiency, could have been used in the lethal injection process. It has now tightened its supply guidelines to ensure it does not happen again.

"This is misuse of our product," said its managing director, Stephen Watkin. "It is primarily designed for saving and improving lives. We are one of five suppliers of this product in the UK and our absolute first concern is the safety of our medicines and our patients."

Vince Cable, the Business Secretary, tightened the rules on the export of sodium thiopental when suspicions emerged it had been supplied to the US by a British firm for use in the lethal injection process. It can no longer be exported for that use.

However, no such restrictions exist for the export of pancuronium bromide and potassium chloride. A spokeswoman for the Department for Business said: "No action is currently being considered against Dream Pharma because it has not broken any laws in selling the chemicals to the US."

Campaigners urged Mr Cable to take urgent action last night. Clive Stafford Smith, head of the Reprieve charity which opposes the death penalty, said that pharmaceutical firms also had to do more to ensure their products did not end up being used in executions.

"It is not sufficient that a business should avoid being irredeemably evil. Rather, it should be ethical," he said. "Recently, we have all learned to despise bankers and their bonuses. Yet when we criticise venal corporations, we tend to forget to demand more than minimally reprehensible behaviour."

The spokeswoman from the Department for Business said that the Government was taking note of the export of the drugs. "Vince Cable has already made clear his personal and the Government's moral opposition to the death penalty. He has already taken decisive action by placing a control order on the export of sodium thiopental and the department is considering a request to place controls on two other pharmaceuticals that are currently used in the execution process in the US."

... and what alavi is accused of selling

Sodium thiopental

A fast-working anaesthetic often used in veterinary operations. It is the first drug injected into a prisoner, bringing about unconsciousness in seconds.

Pancuronium bromide

The next drug administered to the inmate, causing paralysis. Recommended in the protocol for euthanasia in some European countries.

Potassium chloride

Often given to patients suffering from potassium deficiencies in small amounts. Causes cardiac arrest and death when administered at the end of the execution process.