The Home Office collects and publishes information annually on the outcome of misconduct proceedings and criminal investigations involving officers, including the number of officers that have been dismissed following proceedings. However, information on the circumstances that led to a case being brought is not collected centrally by the Home Office
The latest data on the outcomes following misconduct proceedings, which covers cases in the year ending March 2019, are available here: https://www.gov.uk/government/statistics/police-workforce-england-and-wales-30-september-2019.
The College of Policing publish data annually relating to those who have been dismissed from policing and placed on the Police Barred List. The most recent data shows that, in the period ending 31 March 2019, 14 officers were dismissed under the category ‘sexual conduct towards a colleague’. This data is available here: