A puppy saved the lives of its owners after alerting them to a dangerous gas leak in their home.

Four-month-old Saffy, a springer-cross, knew exactly what do to when she smelled gas in the middle of the night.

The puppy, sleeping in owner Joe Marshall's bedroom, woke him in the early hours of yesterday with her persistent barking.

In a feat that would make Lassie proud, Saffy ignored Mr Marshall's attempts to go back to sleep and forced him to accompany her downstairs at their home in Titian Road, Hove. On the ground floor Mr Marshall discovered that gas had been leaking from the hob in the kitchen for four hours.

If he had not been alerted to the danger an ignition boiler would have kicked in three hours later, which could have blown the house to pieces.

Mr Marshall, 35, an ambulance officer, said he and partner Martyn Whitehead, 40, an artist, might not be here today were it not for Saffy, who only arrived from a rescue home five weeks ago.

He said: "We've got headaches but apart from that we're okay.

"It was my fault. I took a pile of laundry off the work surface in the kitchen to take it upstairs. As I did it I knocked the gas hob on.

"I shut that part of the house and went to bed. About 2.20am Saffy woke us up.

"The gas was going for a good four hours by then. We have had her five weeks and she never wakes us up. She normally wakes up about six.

"She just wouldn't let me sleep. I thought she wanted to go out. When I got to the kitchen I was overcome with the gas.

"We are pretty convinced she could smell it. We didn't turn any lights on or any electrical switches. We opened all the doors and windows.

"The boiler is programmed to come on at 5am. It is an ignition boiler. I dread to think what would have happened if that had come on after another three hours." He said Saffy was an "incredibly bright little dog"

who must have been worried by the odd smell.

Mr Marshall added: "I thought I could smell onions when I got up - obviously it was the gas. She could have got a gut feeling. Her sense of smell is 100 times better than ours."

He said he would reward Saffy with lots of turkey and by letting her off for her naughty behaviour over Christmas.

"She had a couple of Asbos against her - she let herself down by chewing up a new handbag strap of my mother's and some Christmas cards.

"She has completely redeemed herself. She is brilliant.

She has always shown great intelligence."

Saffy joined the family after Joe and Martyn's border collie Nipper died last January. The couple moved to Titian Road from Waterloo Street, Brighton, and in November adopted Saffy from the Dogs Trust in Brighton Road, Shoreham.

She was one of a litter of 11 born in the dogs' home. Joe and Martyn have kept in touch with two other families who took a puppy and have been told they too are remarkably intelligent.

Vicky Heaton, assistant manager at the dogs' home, said that when Saffy's mother arrived from Dumfries she was pregnant and emaciated.

"I have one of the puppies.

She is a typical springer-cross, maybe with a Staffy. Both breeds are very intelligent."

Anyone thinking of rehoming a dog can visit from 12-4pm any day except Tuesdays. It is closed on New Year's Day.

A Corgi expert said if petrol gas combines with air it can cause a devastating explosion.