A police officer who was given a suspended sentence after using a Taser on a man at a railway station has had his conviction quashed.
Andrew Spiby, a constable with British Transport Police (BTP), was found guilty of assault following a two-day trial in April.
The 56-year-old had been deployed to deal with a reported disturbance at Derby railway station on 28 May 2018.
The BTP Federation said it is "pleased" by the appeal outcome.
In a statement, the federation said it hopes PC Spiby's case will be used as "guidance" by the Independent Office of Police Conduct (IOPC), which finished its investigation into PC Spiby and a colleague in October last year and then sent a file to the Crown Prosecution Service, which authorised charges in January.
"There is a world of difference between an officer acting with an honestly-held belief about the threat facing them or others, and an officer deliberately and recklessly intending to harm someone," it said.
"The latter is completely unacceptable, but the former is a split-second decision made with the benefit of both training and experience."
In a statement the IOPC said it "determined that PC Spiby had a case to answer for gross misconduct", adding "associated disciplinary matters" will now be discussed with the BTP.
A spokesman for the force said: "We will now consider the court's findings and will discuss next steps with the [IOPC]."