A dog and his 13-year-old owner have been hailed heroes for the discovery and rescue of a man who became trapped head-first in a septic tank in Sydney’s north.

The man, aged in his 40s, was repairing the tank at the property when he became stuck upside down.

The terrifying ordeal was made worse by the water level rising inside the tank.

According to news.com.au, Spot heard the man’s cries and began frantically barking, whimpering and howling on a walk around the property, prompting the teenager to urgently call emergency services.

To save the man, the girl threw a rope into the 2.3 metre deep tank for the man to grab onto, while she waited for help to arrive.

New South Wales Ambulance acting inspector Charnan Kurth told The New Daily  the crews that attended faced a challenging scene as they worked to free the man.

It took paramedics and Fire and Rescue NSW 40 minutes to pull the man the safety before he was taken to hospital in a stable condition with minor head lacerations.

The 10-month-old border collie has been praised for saving the man.

“Had the dog not heard the man’s cries, it may not have been such a good ending,” Inspector Kurth said.