Doggedly determined Jack finds way home in incredible journey

But, 31 hours later, the terrier-whippet turned up on the doorstep of their home in Penistone, South Yorkshire after navigating the 15 miles home.

The dog managed to cross not only the M1 motorway, but major trunk

roads, a maze of streets and moorland hills.

Mr Cooper, an accountant, and Mrs Cooper, a vet, burst into tears when they found the dog, adopted as a stray five years ago, curled up on the doorstep.

Mrs Cooper, 49, said: "I can't explain how he managed to travel so far and cross all those busy roads and the M1 – I only wish I could."

Jack, six, went missing while the Coopers were walking him in Dearne Valley Park, Barnsley.

Mr Cooper, 46, said: "We searched high and low till it was dark, and then carried on the next day after work, moving out of town, and talking to as many people as we could.

"It's around 10 miles as the crow flies, but Jack must have travelled at least 15 miles, negotiating the three main trunk roads and the bypass in Barnsley, and crossing the hills to Penistone without going in any kind of straight line.

Son Rob, 16, says that although the pet appeared timid, it showed that "there's a lot more to Jack than meets the eye."