The following article was published in the Guardian on Friday, 07/11/2008:

A prominent animal rights activist accused of planting petrol bombs at Oxford University was yesterday cleared of possessing an explosive substance - packets of sparklers - with intent.

The verdict in the trial of Mel Broughton, 48, is a setback for the police investigation into a series of attacks aimed at preventing construction of a £20m animal testing research laboratory in Oxford.

The jury at Oxford crown court was unable to reach a decision on two other charges, of conspiracy to commit arson and possession of articles with intent to damage or destroy property. The prosection has asked for a retrial. Broughton was alleged to have caused £14,000 damage when the Queen's College sports pavilion blew up in November 2006.

Two similar bombs were planted under a temporary building used as an office at Templeton college three months later but failed to go off. The bomb attacks were claimed by the Animal Liberation Front on its website, Bite Back, the court was told.

Broughton was accused of having planned and possibly carried out two arson attacks on buildings belonging to the university as part of a "terrorist campaign" against the research laboratory.

The two improvised devices which exploded at the sports pavilion were made with fuel and a fuse operated by sparklers. Two similar bombs were planted under a portable building used as an office at Templeton college in February last year but failed to go off.

The jury heard that the university had been the target of animal rights campaigners since it announced plans in 2004 to build a biomedical research laboratory. Broughton was said to be the leading figure in the animal rights group SPEAK which was set up in 2004 in protest at plans to build the animal experimentation laboratory at Oxford. The jury was told that a DNA sample found on part of the fuse in one of the failed Templeton devices matched Broughton.

When police arrested him at his home in Northampton, in December last year, they discovered 14 packets of sparklers and a battery connector in an unused water tank in his bathroom. Underneath his carpet was a university employee's security pass and a notebook containing a list of those identified as targets for "direct action", the court heard.

Broughton told the court he was involved in organising legal demonstrations against the lab in South Parks Road, Oxford. He denied having anything to do with the bombs. He told the jury that he was "too high-profile" to risk carrying out the attacks, being a well known activist.

The judge, Patrick Eccles, discharged the jury and remanded Broughton in custody until a hearing on a date to be fixed. A new trial is expected next year.

David Bentley, defending, said he wanted Broughton's remand in custody reviewed at the next hearing in the light of the not guilty verdict