A police officer has been placed under criminal investigation after a man was shot with a Taser weapon and left paralysed from the waist down, the Guardian has learned. The man, 23, was shot by an officer using a stun gun as he jumped over a wall and fell as officers tried to detain him in Haringey, north London. The incident happened on 4 May and is being investigated by the Independent Office for Police Conduct (IOPC). The man was arrested for drug-related offences and has been in hospital ever since. The IOPC said that after it had examined the initial evidence one police officer was now subject to a criminal investigation for the alleged offence of causing grievous bodily harm. The police watchdog said the officer “will be asked by IOPC investigators to give a written account under caution. The officer has also been served notice of investigation for gross misconduct.” It stressed it did not mean the officer had done anything wrong. The man’s family are in turmoil after the incident and have asked not to be named. His sister told the Guardian: “It is a tragic time for the family. Emotions are high and there is a great deal of upset. Life has completely changed. He is young. We can’t understand how this has happened.” Sal Naseem from the IOPC said: “Having examined a range of evidence including body-worn video, witness statements and medical evidence, we have taken the decision that this is now a criminal investigation. A criminal investigation does not mean that criminal charges will necessarily follow. “We understand that many people are concerned about this incident and I want to reassure people that this is being thoroughly and independently investigated.” David Lammy, MP for the area where the incident happened, said: “I’ve met with the family and there is definitely community concern about this incident. We need a full and thorough investigation into how he has ended up with life-changing injuries.” Police and the government believe Taser weapons are a vital tool for officers. But they have been controversial because of claims of deaths linked to them, and alleged disproportionate use against black people. Police point to incidents where Taser weapons have saved lives, such as stopping a knife attacker at Leytonstone tube station in December 2015. In the Haringey case the IOPC are expected to examine if deployment of the Taser weapon was lawful and proportionate. They will also see if due regard was taken of the risk posed by firing the electric stun gun as a suspect clambered over a wall. The IOPC are accused by some in policing of subjecting officers to long investigations for little reason. Those who help families accuse the police watchdog of failing to be effective and hold state power to account. The veteran community activist Stafford Scott said: “Community tensions are building. Even though we are on lockdown my phone hasn’t stopped ringing. “No one appears able to hold the police to account for their use. “We are angry but not surprised whatsoever, as it is our experience as a community that the MPS [Metropolitan police service] is an institutionally racist organisation that shows no signs of, or willingness to change.” The IOPC said the incident started when police on patrol approached a man, in his 20s, on Burgoyne Road, close to Finsbury Park. The IOPC said the man “suffered a life-changing injury” and added: “We understand that the man ran off and police officers chased and then Tasered him as he jumped over a wall. The man fell and suffered serious injuries. He was arrested for drug-related offences and was taken to hospital where he was assessed as having a life-changing injury.” Police say they use force rarely and officers are highly trained in the use of Taser weapons, which more and more officers are carrying. Commander Kyle Gordon, the Met lead for firearms including Taser weapons, said: “Taser can be a more appropriate tactical option for officers to resolve an incident and prevent violence escalating than the traditional use of a baton or pepper spray. Of the approximately 9,500 occasions a year a Taser is used in the Metropolitan police district, one is fired just 9% of the time.” The IOPC said it was concerned about claims of the disproportionate use of stun guns against black people and those with mental ill health. Just under 7,000 Met officers carry Taser stun guns and that will rise to 10,000 by 2022, just under a third of the force. The incident in north London was one of several recent ones involving Taser weapons that led the IOPC this week to call for greater scrutiny of their use. Other incidents include use of a Taser weapon, caught on video, by Greater Manchester police on a man outside a petrol station, when his child was nearby. On 6 May a man was stopped in Southwark, London, for a drugs search and was red dotted with a Taser weapon. The IOPC also said it was examining an incident involving West Midlands police, but declined to give further details.