The mobile phone video was posted to YouTube where it has accumulated over 100,000 views. The London police are already conducting an investigation into the matter, and a statement on the force's website says the Taser was used to 'gain control of one of the males involved in the altercation'.
At a hastily-called news conference, London Police confirmed a 17-year-old who was tasered was taken to hospital and another male were in custody.
'Our investigation is unfolding,' Constable Dennis Rivest said. 'There's a number of people that need to be interviewed right now and we still have a lot of work that we have to do to complete this investigation.
'And we're going to wait before any further comment on the situation.'
He would not say if the officer issued a warning before using the stun gun.
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