The trial of a former magistrate accused of making bombs in a bid to kill his ex-girlfriend's new partner was due to enter its second week today.

On Friday, Oxford Crown Court heard that Jonathan Wilkes used a mobile phone registered in the name of a friend to contact companies to buy bomb components.

Inquiries by police into the discovery of nine pipe bombs made out of water bottles in woodland in Freeland, near Witney, and Syreford, Gloucestershire, led them to a company called RS Components in Corby, Northamptonshire.

They found that a man calling himself Mr Cooper had ordered items from the company and had left a mobile telephone number, which was registered to a Mark Brown, the name of a friend of Wilkes from school.

Wilkes, 40, admitted in interview he had bought the phone to ring his former mistress Collette Cooper.

He said he was concerned his new partner might see Miss Cooper's number on an itemised bill.

Wilkes admitted ordering items from RS Components but denied he had used the false name Mr Cooper.

Police investigated the mobile phone calls and discovered Wilkes had called model shops, including one in Milton Keynes which sold rockets.

He also called gun clubs, gun smiths, plumbing suppliers and two manufacturers of metal nuts in High Wycombe.

Wilkes, who claims he was being blackmailed into buying the components, said he was making inquiries to find out what the blackmailer might be planning to use them for.

Wilkes, formerly of Wroslyn Road, Freeland, admits making the bombs, but denies two counts of possessing explosive devices with intent to endanger life and two counts of unlawfully possessing explosive devices.