A dramatic video has emerged of a group of young cyclists circling a biker and allegedly trying to steal his keys and helmet-mounted camera in London, UK.

The footage, shot on Saturday near Westminster Bridge, shows the young men riding next to the motorcyclist until he stops.

Once they come at a halt, one of the cyclists appears to try and grab the biker's helmet camera while another one can be seen putting his hand over the motorbike keys.

"[They] tried to kick my sports bike as I was going to overtake the grey Prius car in front of me," the filmer wrote online.

"It was a very tense situation, I'm pretty sure both them and I were waiting for the other to make the first move to then attack the other," he added.

The biker later explained that boys from the group tried to get in touch with him explaining that this attitude was unusual.

"Olders from the group message me and tell me that these lads are trouble makers and don't represent their group," he said.