Even as more States in the United States deploy a veterinary euthanasia drug to execute death row inmates, a Danish company supplying the drug has been drawn closer into a stormy debate surrounding its use.

Since last year end, States such as Texas, Oklahoma and Ohio have turned to pentobarbital, commonly used to put down dogs, as one of the three components of the lethal injection cocktail. Where it has been used, it replaces sodium thiopental, the drug which had been in use to induce unconsciousness.

This switch followed the announcement earlier in 2010 by the sole manufacturer of thiopental, Hospira, that it would be ceasing production due to various raw materials issues. Since then U.S.-based Danish company Lundbeck has been sought out by correctional facilities for pentobarbital.

With the execution of Carry Kerr in Texas and Jeffrey Motts in South Carolina earlier this month, seven people have been executed using Lundbeck's drugs. While Lundbeck does not officially condone the use of its product in lethal injections, it has not taken sufficient steps to halt it, according to anti-death penalty campaigners.

Reprive, a campaign group based in the U.K., said though it had “asked Lundbeck to investigate a number of possible courses of action to prevent their drugs being used in this way... the firm has so far refused to either adopt these or to explain in any detail why they are not feasible.” Yet, the company is likely to find itself increasingly caught up in allegations of aiding “cruel and unusual punishment” towards death row inmates in the U.S., especially as anaesthesia specialists such as David Waisel of Harvard Medical School have warned that “the use of pentobarbital as an agent to induce anaesthesia has no clinical history... [and] puts the inmate at risk for serious undue pain and suffering.”

Meanwhile Lundbeck also came under fire in its home country this week when a major Danish pension fund, Unipension, sold 40 million Danish Kroner (nearly $8 million) worth of shares in the pharmaceutical company over concerns about the use of their drugs in U.S. executions. It was further reported that Denmark's largest pension scheme, ATP, said “there are still things that need clarification” by Lundbeck concerning this issue.

A Reprieve official, Maya Foa, said: “The moral consequences of being complicit in executions should have been enough to make Lundbeck take action; perhaps now that they are being hit in the pocket, they'll realise they simply cannot afford to ignore this issue for one day longer.”