This is the heartwarming moment a passerby climbed under a building to rescue a stray dog stuck inside.

Watcharaporn Thasomboon and her boyfriend, Jaras, retrieved the hapless, disabled canine after a medicine delivery driver told them about the animal in Surat Thani, Thailand.

This prompted the couple to remove the dog from the rundown structure and adopt it on June 15.

Footage captured by Watcharaporn shows her partner, Jaras, wearing gloves and a face mask, gently dragging the immobilised pooch under a wall.

Watcharaporn said: 'The stray dog had injured legs and couldn't stand or walk properly because of an accident. It had lost its hearing, and its eyesight was very blurry in both eyes due to corneal wounds.

'It had been stuck under a building for about a week. A passing driver found it and asked for help because he had to continue his route and didn't have time to rescue the dog himself.

'If we hadn't helped, it probably wouldn't have survived.'

The pair then drove the dog from Surat Thani to Kantang Pier in Trang Province for treatment.