A shortage in supply has some US states scrambling to find sources or substitutes for the lethal-injection cocktail  EPA]

Germany's health minister is urging the nation's leading drug companies and distributors to ignore requests from the US for supplies of a vital drug used in lethal injections.

A spokesman for Philipp Roesler confirmed on Saturday the minister had written a letter to the nation's leading pharmaceutical companies, "urgently" appealing to them not to respond to requests from the US for the drug, sodium thiopental.

Supplies of the drug are growing short after the sole US manufacturer ceased production. It is still marketed in Germany as an anesthetic.

The shortage of the drug resulted in an Oklahoma inmate being put to death using a veterinary anaesthetic on December 16, 2010.

John David Duty was believed to have been the first to have been executed in a US prison using pentobarbital, a sedative which is also commonly used to euthanise animals.

Although German law does not prohibit sale of the drug abroad, Roesler urged drug companies to understand that its potential use in the US is not in keeping with German and European values.

Source: Agencies