Jurors were told today that a man accused of murdering two squatters in a house fire was an "easy target" because he was a homeless drunk.

James Cox, 63, of no fixed abode, denies killing Sian Sanchez 36, and Howard Blake, 51, in a fire at Redbridge Cottage, Old Abingdon Road, Oxford, on January 2, 2007.

Stephen Mejzner, defending, said "The prosecution is trying to build a case that amounts to no more than suspicion around an easy target."

He told the jury at Oxford Crown Court that they had to consider the possibility the defendant's ex-wife, Alison Cox, had started the blaze.

Mr Mejzner said she had a "predilection for causing fires" and in police interview last March had admitted starting fires at two empty buildings.

He said it was possible a burglar had started the fire, and raised the possibility the fire was caused by a discarded cigarette. He pointed out there was no trace of accelerant on Cox's clothing. Mr Mejzner dismissed CCTV footage which placed Cox near the scene of the fire as "of limited value" as it did not show the cottage itself.

He attacked the credibility of prosecution witness Michelle Wilson who claimed Cox had confessed to starting the fire, saying she was an alcoholic with criminal convictions.

The trial continues and the jury is expected to retire to consider its verdict tomorrow.