Switches used in a home-made bomb that blew up and badly injured a businessman had been poorly constructed, a court has heard.

It is alleged that 43-year-old Jonathan Griffiths had been building the device to send to another businessman who owed him thousands of pounds.

Mr Griffiths and the house owner Geoffrey Wildy, 58, are charged with having explosives with intent to endanger life and with carrying out an act designed to cause an explosion on 4 October.

Fire officers were called to the blast house

Cardiff Crown Court heard the pair had intended to send letter bombs to Ken Jones, of Dinas Powys, south Wales, and Gary Smolinski, of Penylan, Cardiff.

But the home-made bomb detonated, half destroying a semi-detached house at Brynna near Bridgend, south Wales.

Mr Griffiths suffered severe injuries, losing both hands and burns and injuries to his genitalia and abdomen. He also suffered a perforated ear-drum.

Explosives expert Hazel Cullum said the switches on the bomb had been 'over-engineered'.

The jury heard the detonator on the device had been enough on its own to cause "substantial damage" to a person.

Their method of settling an old score was deadly

Greg Bull, prosecuting

Letters addressed to the intended victims of the bombs had been found in the hallway of the house.

Gregory Bull, prosecuting, told jurors that former oil executive Mr Griffiths and business partner Mr Wildy had planned to "bring terror and carnage".

Mr Bull said former engineer Wildy had the knowlege to build pressure switches for the explosives.

It is alleged Griffiths had procured the restricted use plastic explosive known as PE4 from an unknown source.

Bomb disposal experts prepare to examine the car

"But the bomb literally blew up in his face," he said.

"They had intended to settle an old score. Their method of settling this score was deadly.

"They intended to send letters packed with British military plastic explosive, detonators and pressure switches which, when opened, would blow up in the recipient's hands and face."

The court heard that the two men had met while working in the oil industry in Libya and that both had been defrauded by businessman Ken Jones.

'Blackened flesh'

PE4 explosives were found in a garage workbench at Mr Griffiths' Cambridgeshire home as well as letters addressed to South Wales Police which blamed the attacks on a well-known Cardiff criminal.

The father-of-three was critically ill after the explosion, but was able to sit at the court for the trial, requiring amplified headphones to hear evidence.

Jurors were shown a video of the scene at the kitchen, the walls of which were spattered with the defendant's blood and blackened flesh.

Mr Wildy earlier told detectives he had not known what his alleged accomplice was up to in his kitchen and denied holding a grudge against Mr Jones.

Griffiths admits a charge of having an explosive substance.

Wildy, of Meadow Rise, Brynna, and Griffiths, of Kirk Gate, Wisbech, Cambridgeshire both deny having an explosive substance with intent and committing an act with intent to cause an explosion.

The trial continues.