Priya Ramnath, 60, who worked in Britain's National Health Service, injected Patricia Leighton, an intensive care patient with adrenaline against the advice of three colleagues in the Stafford District General Hospital in July 1998.

Ramnath, who now lives in the US, was convicted of the patient's murder and handed the suspended jail sentence at the Birmingham Brown Court for going against the wishes of three colleagues and failing to speak to a consultant anaesthetist at the hospital before injecting the drug into Leighton.

The doctor came back from the US in Feb, 2008 to face the charge after being threatened with extradition. The jury found her guilty by a 10-2 majority while Ramnath denied manslaughter by gross negligence.

Leighton died from heart failure shortly after she was injected with the drug. The prosecuting lawyer, Michael Burrows, told the trial that she was being treated in an intensive therapy unit in the early hours of the morning.

He said that within moments of the injection Leighton jerked forward in her bed and exclaimed: "What's happening to me? I am going to die." She lost consciousness shortly afterwards.

Members of Leighton's family were present in court throughout the trial, including her daughters Debbie Leighton-Newton and Nicky Fellows.

Justice Rafferty ruled that the interest of justice did not require her to take away Ramnath's liberty. She said Ramnath, who has two children and lives in the US, panicked in the ‘pressure cooker’ of the hospital's intensive therapy unit.

She added that Ramnath's defining error was that she had chosen not to listen to a senior nurse working alongside her.

"Arrogance has cost you your reputation," the judge said.

Speaking after the hearing, Detective Chief Inspector Phil Bladen, of the Staffordshire police, described the inquiry as complicated and highly unusual.