Former PC Liam Mills, 34, pleaded guilty to two counts of misconduct in a public office and a data protection offence at Sheffield Crown Court yesterday, and is set to be sentenced on September 30.
Mills resigned from the force, and an accelerated misconduct hearing went ahead in his absence - which found he would have been dismissed.
He will never work in policing again after being placed on a barred list, force bosses confirmed.
It comes just weeks after PC Nabeel Khan, 25, was given a two-year jail term for dealing drugs on Barnsley’s streets after an investigation by South Yorkshire Police and the Independent Office for Police Conduct.
Deputy Chief Constable Tim Forber said: “I am acutely aware of how appalled our communities will rightly be to hear about the offences committed by Mills, a former police officer.
“I and colleagues across the whole force are equally appalled.
“There is no place for such behaviour in South Yorkshire Police and when others in Mills’ team became aware of what was happening, they followed the appropriate procedures.
“Mills was immediately suspended from duties and a thorough investigation took place which uncovered the offending.
“I hope this case demonstrates the force’s commitment to rooting out those who do not reflect the true values of policing and provides assurance that we will always deal with such matters as swiftly and robustly as we possibly can.”