Dog shuts down major Sydney tunnel after escaping sitter's home

A family dog has forced the closure of a major Sydney tunnel after escaping from his sitter's house.

Darcy the border collie was staying at a home in West Ryde one day last month when he snuck out through an unlocked gate about 2am.

Incident controllers spotted him in the Lane Cove Tunnel, closed the westbound lanes and blocked traffic from entering and intercepted him.

"A black dog, in a black tunnel, at 2am in the morning. The way these fellas, even to spot him... they're doing a marvellous job," dogsitter Greg Bones said.

Incident Controller Scott Ewers said his colleague Chris was the one to get Darcey on the leash and back to safety last month.

"Chris used his dog whispering skills and the dog came to him," he said.

Chris said he was doing his job and keeping people safe.

"It's about the safety of the public, because they see a dog and they panic."

His owner is convinced he was heading home to Northbridge.

"Oh, he was going home," Glenda Bones told 9News.

She is "very happy and grateful" to have the three-year-old home.