A magistrate facing explosives charges bombarded his ex-mistress with messages when she ended the relationship, a court was told.

Collette Cooper told Oxford Crown Court she finished the affair with Jonathan Wilkes, 40, in November 1999.

She said Wilkes wanted to keep track of her whereabouts. He began sending her text and voice messages, although she told him she was going out with a man called Howard Davies.

Miss Cooper, 30, said Wilkes' calls eventually stopped when she became pregnant to Mr Davies.

She said: "I think he just fell tired of it. Also, I fell pregnant and told Jonathan about this. It was probably around that time that the harassment calls and text messages stopped."

The prosecution alleges that Wilkes made pipe bombs, found in woodland in Freeland, near Witney, in August 2000, and in Syreford, near Cheltenham, intending to use them against Mr Davies.

Miss Cooper said she met Wilkes when they worked together at Swindon-based company PHH.

By the time Miss Cooper left the company, in November 1998, they had become lovers.

Wilkes then started working for Hewlett Packard, in Bristol, and went to Belgium at weekends where his wife Annie Henriot was working.

The jury was told police invited Wilkes to Witney police station to complete a fictitious form because his firearms licence had expired.

Police actually wanted to get his fingerprints without alerting him to their investigations.

But Christopher Sambrook, a civilian working for Thames Valley Police, said when Wilkes arrived at Witney police station to complete the form he had plasters over his finger tips.

Mr Sambrook said Wilkes told him he was suffering from a skin complaint.

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

The trial continues.