A partner at international firm Dechert is suing a corporate surveillance firm for £100,000, alleging that investigators installed cameras on his property, followed him onto a private Caribbean island and monitored him on an aircraft.

Neil Gerrard, global co-head of Dechert’s white collar and securities litigation practice, accuses Diligence International of trespass, harassment and the misuse of private information.

Gerrard, who is embroiled in a long running dispute with mining company ENRC, is seeking up to £100,000 of damages from the investigation firm, claiming he had suffered ‘great alarm, anxiety and distress’.

According to the claims form put forward by Gerrard and his wife, a video camera was tied to a tree branch at the entrance of the Gerrard’s house, linked to a hide on neighbouring land. The hide was allegedly covered with chicken wire and foliage and contained technology that enabled remote access to the video camera on a live, real-time basis.

On another occasion, investigators reportedly tried to access a private Caribbean island where Mr and Mrs Gerrard were holidaying with friends by pretending they were Gerrard’s nephews. The authorities smelt a rat when the operatives referred to the claimants by the wrong names.

Two investigators also allegedly monitored the couple on the plane to the Caribbean and a second attempt was made to access the private island after the first attempt proved unsuccessful.

At least two Diligence operatives have been questioned by the British police in relation to the allegations, according to the court documents.

Gerrard is in a long-running battle with the Kazakh mining group ENRC, which is subject to an ongoing Serious Fraud Office investigation. ENRC is suing Neil Gerrard after he allegedly leaked information to the SFO, having been brought in as a lawyer to lead the ENRC internal investigation. He denies the allegations.