Engineering giant Dyson and its rival, Bosch, are locked in a bitter legal battle after Dyson accused Bosch of stealing business secrets by planting a mole in the company.
Dyson, known for its cyclonic bagless vacuum cleaners, has filed a claim in the high court alleging that company secrets had been passed on to Bosch by an insider.
Bosch has refuted the accusation.
Dyson alleged that its German competitor has been acquiring confidential information for nearly two years.
Dyson claimed that the mole was Chinese and worked in a part of Dyson where security was high. It has been suggested that the mole worked in Dyson's advanced motor development team in Malmesbury, Wiltshire.
The company has refused to divulge any other details either on the magnitude or the nature of the leak.
"Dyson has confronted Bosch with evidence of wrongdoing but it has refused to return the technology. Nor has it promised not to use the technology for its benefit, forcing Dyson to take legal action," said a company statement.
The alleged secrets have also reached Bosch's Chinese motor manufacturers through its British base, claimed Dyson.
The company has a track record of fighting to protect its intellectual rights.
"We have spent over 15 years and £100m developing high-speed brushless motors, which power our vacuum cleaners and Airblade hand dryers. We are demanding the immediate return of our intellectual property," said the firm's research and development director Mark Taylor.
Bosch said: "Dyson employed an individual with a pre-existing consultancy agreement with Bosch Lawn and Garden Ltd in relation to garden products, and not vacuum cleaners or hand dryers as Dyson implies.
"Bosch has sought to establish the full details of what occurred, including attempting to establish from Dyson what, if any, confidential information supposedly passed between Bosch and Dyson.
"Bosch regrets that Dyson has chosen to issue legal proceedings and a press statement at this stage, but will continue to act in the appropriate way."