A pensioner suffered horrific burns after falling unconscious on a sofa during a fire at her home.

The woman, who is thought to have been drinking, did not move as the blaze engulfed her sheltered-accommodation flat.

Firefighters called to the scene did not discover her badly burned body until after the blaze was out.

Adur Deputy District Commander Mark Obsborne said: "The scene was pretty horrific for all our boys and I pay tribute to their work."

It is thought a discarded cigarette started the fire in the flat at Milward Court, Wilmot Road, Shoreham, at about 7pm.

Firefighters, including retained and full-time officers from Shoreham and Lancing were sent to the scene after an automatic alarm system alerted them.

Residents had been evacuated from the four-storey building but wardens were unable to confirm everybody was out.

A search of the building was carried out and nobody was found.

But when firefighters entered the ground-floor flat and put out the fire they found the woman.

Shoreham officer Trevor Peacock was one of the first to find the elderly woman on the sofa and thought she may have already died because of her severe injuries.

But she responded to a light being shone in her eyes and was immediately given first aid by the fire crews and paramedics.

She was taken to Worthing Hospital and then transferred to the burns unit at Queen Victoria Hospital, East Grinstead, where her condition was last night described as critical.

Speaking at Shoreham fire station yesterday, officers said the blaze was one of the most serious in recent memory.

Mr Osborne said he had only experienced victims with such severe injuries on a handful of occasions.

He said: "She suffered the most serious kind of burns to a large part of her body and it is very rare for somebody to survive something like this."

A dog was also rescued from the flat and given oxygen before being handed to a vet.

Caroline Tiller, executive director of James Butcher Housing Association, said: "Obviously our thoughts are with the relatives of this lady.

"We are pleased the alarm system worked properly and we are currently investigating the circumstances surrounding this fire.

"We are working closely with the fire service to find out exactly what happened and to see if there are improvements that can be made here in the future."

Mr Osborne said his officers had had "very fruitful" talks with staff from the housing association yesterday afternoon about possible safety improvements at the flats.

The Health and Safety Executive, which investigates most accidents in places of work, confirmed it was not investigating the incident.