An innocent couple are fighting for their lives with horrific burns after a suspected drug gang torched their home by mistake.

Charlie, 66, and Chris Fearn, 59, were last night critically ill in hospital, with their three anxious sons keeping vigil by their bedside.

Their family described them as a caring, community-minded couple "without an enemy in the world".

Mr Fearn is also trying to recover from a broken back which he sustained as he and his wife leapt out of their upstairs bedroom window in fear for their lives.

Intense flames rapidly engulfed their home after the arson attack in the early hours of Monday morning.

The couple have not been able to speak of their ordeal since the attack because they were so badly injured have been kept barely conscious under medication.

Their three sons have spoken of their despair in a bid to find more witnesses with vital clues.

Speaking exclusively to The Argus, their youngest son Stuart said: "There are not words to express how we are feeling. Our mum and dad didn't have an enemy in the world and we are gobsmacked and ridiculously hurt by what has happened."

Mr and Mrs Fearn jumped 20ft from the window of their home in Whitebeam Road, Durrington, Worthing. Police believe the arson, in which someone poured petrol over the Fearn's front door and set light to it, may have been carried out by a drugs gang which targeted the wrong house.

Mr Fearn fractured his spine in at least two places in the fall and doctors are unsure whether he will be paralysed. He suffered burns to 16 per cent of his body including his left arm and chest.

Mrs Fern suffered ten per cent burns and both have been sedated and have been on a ventilator since they arrived at Worthing Hospital.

The couple's three sons Darren, 39, Lee, 36, and Stuart, 31, have been by their bedside since the attack.

Stuart, who lives in Sompting with his wife Alix and their two children, said: "We are certain this attack was not meant for our mum and dad.

"They were well loved and respected and I am quite certain no one had a bad word to say against them."

Neighbour Patrick Burke and his wife Mavis moved into Whitebeam Road at the same time as the Fearns.

Mr Burke, 74, tried to rescue Mr and Mrs Fearn on Monday with another neighbour. He managed to catch Mrs Fearn as she dropped from the window but was unable to do the same for Mr Fearn.

Mr Burke said: "I could hear them screaming for me to save them. It was awful. They are a great couple and they didn't deserve this."

Detective Inspector Rob Walker, who is leading the investigation, now known as Operation Trend, said police were keen to speak to a man seen running away from the Fearns' house just as the petrol exploded.

The man was described as white, 5ft 9in, stocky build, with short light brown or blond cropped hair. He was wearing a black Puffa jacket, possibly with a white stripe down the arms, a dark hooded top and dark trousers.

Police are offering £1,000 for information leading to an arrest and conviction.