The report said the SDEA should have armed support

HM Inspector of Constabulary also found the Scottish Drug Enforcement Agency has failed to recruit sufficient women.

The SDEA was set up six years ago to combat organised crime including drug trafficking.

Graeme Pearson, director of the agency, has previously called for his officers to be allowed to carry guns.

The HMIC report, published on Thursday, said the SDEA has been forced to rely on gun power from local forces.

The report said: "There is a long-recognised need for the agency to have access to specialist firearms support for operations where there is an identified possibility of confronting armed criminals."

Mr Pearson said he welcomed the comments on the need for firearms cover.

It can be very difficult to reach out to women and attract them to the agency direct Graeme Pearson

He said the agency was awaiting the outcome of a national study into Scotland's police firearms requirements.

HMIC assistant inspector Malcolm Dickson said the issue must be addressed and that it was necessary to provide round-the-clock cover for officers.

The report also revealed that the percentage of women police officers in the SDEA in March 2006 fell to 11.6%, compared with 12.6% three years ago.

This was despite an order to improve the gender balance after an inspection in 2003.

The report suggested that the force should question its employees to identify what the "barriers to entry" for women were.

Mr Dickson suggested that a change in culture might attract more female recruits.

Mr Pearson said two of the SDEA's eight senior operatives were women

"It can be very difficult to reach out to women and attract them to the agency direct," he added.