A SENIOR Scottish army officer has been sent home from Islamabad in disgrace after being caught by MI6 in an "inappropriate relationship" with a Pakistani female intelligence agent.

Brigadier Andrew Durcan, 56, has been relieved of his post as defence attache.

Although sources said yesterday that there was no suggestion of sexual misconduct by the married brigadier, he had developed a close friendship with the woman, who was identified by UK security officials as an undercover operative for Pakistan's ISI intelligence agency.

The shadowy Pakistani spy agency was instrumental in setting up and supporting the Taliban regime in neighbouring Afghanistan in the 1990s.

Rogue elements within its ranks have maintained contacts with the ousted Islamic hardliners and are also believed to have links to the al Qaeda terrorist network.

Brigadier Durcan is a former commander of the Gordon Highlanders, 52nd Lowland Brigade and deputy inspectorgeneral of the Territorial Army.

The Ministry of Defence, which seconds senior officers to the Foreign Office as military attaches in embassies around the world, refused to comment on Brigadier Durcan's future.

However, officials confirmed that he had been relieved of his post because he had "lost the confidence of the High Commission in Pakistan".

Security sources say the ISI agent's cultivation of the friendship with the Scots officer appeared to be aimed at gaining access to his social and professional circle among military, embassy and intelligence staffs of allied nations.

The scandal comes a few months before Britain is due to deploy a 3500-strong brigade to Afghanistan to help in the hunt for Taliban and al Qaeda fugitives along the Pakistani border.

It has also developed in the middle of negotiations between Britain and Pakistan over stricter surveillance and regulation of the radical Islamic madrassa religious schools visited by some of the July 7 London bombers and other young UK Muslims in recent years.

Brigadier Durcan, who was nicknamed "the tartan barrel" by officers under his command in Scotland because of his girth, has been cleared of passing any secrets, but was yesterday described by diplomatic sources as "naive for an officer of his experience".

The unnamed woman is said to be a defence academic with enough military knowledge to take advantage of unguarded snippets of information.

A source said: "The lady was a threat because of her ability to eavesdrop and comprehend the import of 'shop talk' among military attaches at embassy functions and social gatherings.

These are the lifeblood of the Western scene in Pakistan, where opportunities for entertainment are relatively few and far between.

"Attaches are always warned of the dangers of entrapment.

The honeytrap is as old as espionage itself. Although there is no question of a sexual liaison in this case, the theory and practice are the same. Islamabad can be a lonely, if busy, posting.

"There is no doubt that the individual concerned in this episode is an ISI agent. Despite President Musharraf's attempts to purge the ISI of its radical Islamic elements, Western security organisations remain deeply suspicious of some of its loyalties."

An MoD spokesman confirmed that Brigadier Durcan had been dismissed as military attache, but said he had been cleared of misconduct and remained a serving officer. He declined to discuss the brigadier's future postings or whereabouts.

"The high commissioner in Islamabad considered his platonic friendship with a Pakistani national inappropriate and, as a result, lost confidence in him, " he said.

"He has been investigated and cleared over potential breaches of security."