The humble location of Dream Pharma, which doubles as a driving school
It would be hard to imagine a more humdrum and banal place than 176 Horn Lane in Acton, west London.
Sandwiched between two blocks of flats, the modest office is home to both Elgone Driving Academy and a tiny, unconnected, pharmaceutical company that supplies the drugs used in lethal injections.
dated 28 September 2010 and obtained under Freedom of Information legislation shows that the company Dream Pharma Ltd supplied the state of Arizona with the three drugs needed for the execution of convicted murder Jeffrey Landrigan.
Documents at Companies House show that the main registered shareholder is Mehdi Alavi, 50, who describes himself as a wholesaler.
Mr Alavi declined to give an interview, claiming he had "no idea" why Carson McWilliams, the warden of the Arizona State Prison Complex, had ordered the three drugs: the anaesthetics sodium thiopental and pancuronium bromide, and potassium chloride, which is used in a diluted form to treat people with potassium deficiency.
But Clive Stafford Smith, the Director of Reprieve UK which supports prisoners on Death Row in the US, dismissed Mr Alavi's claim of ignorance over the intended use of the drugs and said that the combination of the three substances could have only one purpose.
"The invoice from Dream Pharma has enough Thiopental injection to execute ten people in Arizona, so certainly there's ten people dying," he says.
"Unfortunately we can say, without fear of contradiction, that one person is already dead from this and that's Jeffrey Landrigan who was executed on 26 October. He died with British drugs apparently."
The use of British drugs in US death chambers alarms charity Reprieve
The date of the Dream Pharma invoice, 28 September 2010, corresponds to an email sent on the same day between prison officials in Arizona and the neighbouring state of California.
Charles Flanagan, the deputy director of corrections for Arizona, wrote to John McAuliffe, of the Californian Department of Corrections and Rehabilitation. The subject was "execution protocol drugs".
"John, as we discussed on the phone today, we have purchased the drugs we need from a company in London," he wrote.
"Frankly, there was no possibility of getting the Sodium Thiopental from any source in the US to include from any of the departments of corrections in other states that use the same three drug protocol.
"We were able to purchase enough of the drug in our protocol for each of the forthcoming executions."
The correspondence also establishes that on the day after this email, Arizona agreed to supply California with a quantity for its own executions.
But most states continue to find it increasingly difficult to acquire the drugs needed for executions, particularly sodium thiopental.
Last month, the convicted murderer John David Duty was executed with an alternative used by vets to euthanise animals, pentobarbital.
Clive Stafford Smith is threatening legal action against Dream Pharma and also called on pharmaceutical companies worldwide to sign an agreement to explicitly prevent the use of their drugs in executions.
Landrigan's execution was delayed by a shortage of a lethal injection drug
"It seems to me that the pharmaceutical companies need to get together and agree to some Hippocratic Oath whereby they only sell their drugs for positive purposes and not to execute people," he says.
In November, Business Secretary Vince Cable announced restrictions on the export to the US of sodium thiopental. Mr Stafford Smith is also calling on the government to prohibit the export of the two other drugs used in the protocol.
A spokesman for the Business Secretary said that 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 currently considering a request to place controls on two other pharmaceuticals that are currently used in the execution process in the US.
"Any decision on this request to place export controls on potassium chloride and pancuronium bromide will be based on fact and assessed against the likely effectiveness of any export control against the impact on legitimate trade."
A spokesman for the Elgone driving academy said, "although his company and Dream Pharma share the same building, they are totally unconnected organisations."
Invoice showing that Dream Pharma invoiced the state of Arizona for three drugs needed for lethal injection