Tongan Police have launched an investigation into a horrific online video showing a police officer brutally beating a teenager appeared to be a high school student.

Grant O’Fee, Tonga’s Police Commissioner after watching the video vowed the officer responsible must be held acountable.

The video was uploaded to Facebook yesterday by a person known as Sione Langi.

It quickly attracted 120 outrageous comments within hours with many expressing astonishment the video shows to prove police brutality against their own people still exist in Tonga.

The video shows a man in police uniform running after the teenager. He beat him to the point the teenager fell to ground while the officer continued to kick him. In the end he struck him with an object appeared to be a stick.

The reason behind the beating is unclear, but according to the recording, it appears the incident happened after a brawl broke out among school students.

O’Fee said they received a complaint and a full Investigation is underway.

“We have not backed away from this issue and we won’t start now,” says Commissioner O’Fee.

“This is a serious blow to our effort to gain the trust and confidence of the public, nonetheless we will pursue this complain vigorously.”

The incident emerged after two Tongan police officers have been jailed last month  for the manslaughter of Auckland constable Kali Fungavaka in August 2012. The 38-year-old father-of-five died in Nuku'alofa a week after receiving severe beatings in a police cell.

Police asked for anyone with information regarding the video that could help with the investigation to contact witness4tongapolice@gmail.com which the Commissioner has full access to or contact Phone Number 21 626 or mobile number 771 6810”.