A policeman has been cleared of attacking a teenage suspect by stamping on him while he was in custody.

A jury found Newham police constable, Joseph Harrington, not guilty of assault occasioning actual bodily harm on Friday – but the officer could still face police disciplinary proceedings for gross misconduct it emerged today.

Prosecutors had claimed Pc Harrington, 29, assaulted the boy, then 15, while he was being held in custody in Forest Gate police station.

But the Met officer insisted he was just restraining the youth because he’d become aggressive in a caged area near the custody suite on August 11, 2011.

The boy, who is now 17 and cannot be named for legal reasons, told Southwark Crown Court he had laughed at Pc Harrington before the enraged officer stamped on him.

Duncan Atkinson, prosecuting, suggested Harrington had “had enough” because he was exhausted from policing the capital during the riots, which had happened just days earlier.

But the jury believed the Pc, who lives in Walthamstow, when he denied using unnecessary force and insisted he was simply following his training.

Despite the verdict, the Independent Police Complaints Commission (IPCC) – the police watchdog - has urged Scotland Yard to bring its own hearing.

IPCC Commissioner Mike Franklin said: “Our investigation concluded the force used by Pc Harrington was neither reasonable nor was it proportionate.

“IPCC investigators spoke to a number of witnesses, who were in the custody area at the time of the incident and, whilst he may have been verbally provocative, he was not displaying signs of violence towards any officer.

“In light of Pc Harrington’s acquittal, it is now for the Metropolitan Police Service to decide if his actions are a breach of the standards expected of police officers and I urge them to seriously consider the issues identified in our report.”