Comedian Ricky Gervais faces a bill for £650 after his neighbour's missing dog was found in Portsmouth, Hampshire.
Ricky Gervais is currently on tour with his stand-up act
Elsa, a Staffordshire Bull Terrier, went missing in Russell Square, London, in January and local resident Gervais saw posters appealing for information.
Lisa Murray, who owns the missing dog, said Gervais had offered to increase her reward offer from £350 to £1,000.
She said: "I am ecstatic to have Elsa back. I can't thank Ricky enough for his help in finding her."
The dog was apparently bought in north London and then taken to the south coast before the purchaser saw publicity surrounding the loss.
Ms Murray said: "I was sent an e-mail saying they might have Elsa but we couldn't be sure until her microchip was checked this morning.
"Once that was confirmed I was over the moon. She looks happy and healthy, it's a real happy ending."
London has seen a sharp rise in thefts of bull terriers in the last year.
According to the Metropolitan Police, 417 dogs were kidnapped in 2005/2006, up 74% from the previous year.
More than half of the dogs taken were Staffordshire Bull Terriers, with many taken as puppies.
Police believe some of the animals are being used to guard "criminal assets".