This is the heartbreaking moment a grieving pet dog helped bury its dead friend.

Footage shows the pooch slowly pushing dirt using its nose and paws while its departed friend lay motionless in the pit in Samut Prakan, Thailand, on January 4.

Pet owner Sirintha dug the grave in her backyard to become the final resting place for her dog, Taohoo, who succumbed that morning after several weeks of illness.

Sirintha and her family members gathered around the pit to say their goodbyes to their beloved nine-year-old pet.

However, they were surprised when the dog’s ‘younger brother’, Samlee, helped to bury his dead pal.

Sirintha said she was holding back her tears after witnessing her devoted pet pooch repeatedly push down the soil using its little nose.

She said: ‘My dog, Samlee, appeared to be heartbroken that his friend was gone. My pets are all very close as they play with each other every day.’

Sirintha added that the dog waited for at least two hours on the grave before it left to return inside the house as if it was mourning. It curled up in a quiet corner and didn’t eat any meals all day.

The pet owner said: ‘My dog is very smart and understands emotions. They are like real people to me. They are family members.’