A RIOT cop was allegedly taped trying to fit up an injured student during a tuition fees protest.

The PC apparently forgot he was wearing equipment often carried to record suspects as he chased the 20-year-old.

He detained the student, who suffered a chipped tooth during the incident on December 9, after he breached a cordon.

The Met officer then discussed making up reasons to arrest him with two colleagues, internal investigators believe.

All three are on restricted duties and warned they face a criminal probe for conspiracy to pervert justice. They could also be sacked.

The allegations surfaced after the student complained that police had used unreasonable force to detain him in Trafalgar Square, Central London.

Bosses listened to the tape and referred the case to the Independent Police Complaints Commission.

Commissioner Rachel Cerfontyne said: "We are investigating a serious allegation that an officer colluded with colleagues to arrest a man on false grounds. We will also look at how he got a broken tooth."