A jury trying a man over the deaths of two firemen following a huge explosion at his family-run fireworks company retired to consider its verdicts for a third day today.

Nathan Winter, 25, is accused of two counts of manslaughter after retained firefighter Geoff Wicker, 49, and support officer Brian Wembridge, 63, were killed in the blast at Festival Fireworks UK Ltd at Marlie Farm in Shortgate, near Lewes, East Sussex.

Judge Mr Justice Cooke, sitting at Lewes Crown Court, gave the jury a majority direction before he sent the jury out to deliberate this morning.

Nathan Winter's father, company owner Martin Winter, 52, was yesterday found guilty of manslaughter while the jury also found the firm, now called Alpha Fireworks Ltd, guilty of two counts of breaching health and safety legislation.

As well as killing the two firemen, both long-serving members of East Sussex Fire and Rescue Service, the blast on December 3 2006 injured some 20 others, mainly police and fire officers.

Jurors heard that Martin Winter was 'grossly negligent' as he knew an unlicensed metal container packed with fireworks could explode if a blaze broke out.

Prosecutors alleged that Nathan Winter was also familiar with the different hazard classifications given to fireworks and their potential for mass explosion in a confined steel container.

The father and son, who live on Marlie Farm, both denied two counts of manslaughter.

During his defence case jurors were told that Nathan Winter could not be considered responsible for the two deaths as it was the duty of fire officers at the scene to be aware of the dangers of a blaze involving fireworks and to take the necessary precautions.

It was also suggested during his evidence that his concerns to keep the flames away from the container were not taken seriously enough by fire officers.

The jury was sent home for the night and will renew its deliberations from 10am tomorrow.