Video has emerged showing a man in a wheelchair being tipped into the road by police in San Francisco.

The man in a motorised wheelchair is seen hanging in his seat by a belt as an officer sends the mobility vehicle over the kerb.

Police in the Californian city have launched an investigation in to the incident, involving a man named Devaughn Frierson.

Watch the video below shot by a witness in the neighbourhood of Visitacion Valley.

According to local reports, it began when one of Frierson's friends was stopped by police and the wheelchair user went over to help out.

An officer tried to move him along by grabbing the chair, before a colleague stepped in and nearly tipped Frierson on to the road.