The same techniques were being used to stop some Australian companies tendering for lucrative projects, particularly in the engineering field.

The detective, Frank Monte, 27, said he had been asked by several overseas agencies to carry out this type of blackmail on their behalf.

He had refused to have any part in the deals.

Mr. Monte, a former member of the police licensing branch, said some Australian companies were also using these "horrifying" techniques to uncover competitors' production and sales secrets.

But these activities were confined mainly to European and American companies with interests in the Australian market.

"Cleaners" planted

Mr. Monte said the companies involved retained private inquiry agents and sent them to Australia to find out everything about specific markets.

On arrival the agents recruited intelligent women and planted them as cleaners in offices and factories.

Their task included searching waste paper baskets and rifling filing cabinets and desks in search of vital information.

Other women were chosen for their beauty and seductiveness and set up in comfortable apartments.

The agents would then arrange a meeting between their victim - usually the managing director or general manager of a company - and the girls.

It was then only a question of time before the girls lured the men into their apartments and into bed.

Cameras and recording devices were skillfully hidden throughout the apartment.

The businessmen were then confronted with the evidence and forced to provide information.

Several small companies had been put out of business by this process, thus leaving particular fields open to foreign domination.

Mr. Monte said agents had sometimes sent trained saboteurs into factories to disrupt production.

He said industrial espionage was a multi-million dollar a year racket and was far more widespread than industry was aware.

He had recently returned from an extensive world tour on which he had studied the latest "strong arm" espionage techniques as well as the most sophisticated electronic listening and watching devices.