The officer had the drug for his personal use

Sergeant Graham Padgett, 37, was cautioned after admitting being in possession of the class A drug.

The officer, who is based at Bedworth police station, is believed to have had a small amount of cocaine for his own personal use.

The force said on Wednesday that a 37-year-old officer had been interviewed for possessing of a controlled substance pending the outcome of an internal investigation.

I think there is a need with certain criteria and guidelines for drugs testing (police officers) Paul Tonks West Midlands Police Federation

The scandal comes ahead of a meeting held by West Midlands Police where the subject of compulsory drugs testing within the force will be discussed.

Paul Tonks, from the West Midlands Police Federation, said it might be time to introduce the measure.

"It's an issue that is certainly high profile at the minute.

"I think there is a need with certain criteria and guidelines for drugs testing.

"However we've got to be very careful about how we take this process forward."

'Widespread drug-taking'

Professor David Wilson, a criminologist who has been researching a book about drug-taking in the police, said some of the officers he interviewed routinely flout the law.

"They advised the suppliers about where to hide drugs, what to say if they were arrested, what to do if they came into the police station.

"That for me was the most surprising element of the research that I conducted and clearly indicates how widespread drug-taking was amongst this sub-group of officers."

West Midlands Police is due to hold its meeting about drugs testing all of its 8,000 officers next week.