A former Oxfordshire magistrate accused of building bombs to kill his ex-mistress's new boyfriend claims that he built them to carry out an elaborate suicide plan.

Jonathan Wilkes, 40, told Oxford Crown Court yesterday he searched the Internet to try to find a way of killing himself which would not look like suicide.

Adrian Redgrave QC, defending, asked gun enthusiast Wilkes why he had not chosen to shoot himself. He said he wanted it to look like an accident.

Wilkes is accused of building nine bombs found at Freeland near Witney, close to his former home in Wroslyn Road, and in Syreford, near Cheltenham, to blow up his former girlfriend's boyfriend.

But Wilkes told the court yesterday he deliberately left the bomb in Syreford so it would be discovered. He connected it to a flat battery, so it could not explode.

He said: "I wanted to give the impression over a period of time of someone building these devices and setting them off for an unknown purpose, so when the one I would use on myself went off it would be part of a pattern."

He said he intended to kill himself using a bomb which would trigger when moved.

Three of the devices found in Freeland were set up in this way. He said he had not intended for these devices to be found.

Cross-examining Wilkes, Simon Mayo, prosecuting, told Wilkes he had "lied and lied again". Wilkes admitted he had lied to the police, to his wife Annie Henriot and to his former mistress, Collette Cooper.

Wilkes claimed he was being blackmailed by an unknown person who threatened to tell his wife he had been having an affair with Miss Cooper and this was making him stressed.

He denied two charges of possession of explosive devices with intent to endanger life and two charges of unlawful possession of explosive devices.

The trial continues.