Local newspaper journalist Sally Murrer was arrested and charged on Monday over the alleged leaking of sensitive information to the Press by her police contacts.
Murrer, a part-time member of staff at the weekly Milton Keynes Citizen, was charged by detectives after allegations that officers had been feeding her tip-offs and stories.
Her alleged sources, Thames Valley Police officer Jonathan Kearney (known as Mark) was charged with eight offences of wilful misconduct in a public office.
He has since retired from the force.
Hertfordshire Police officer Derek Webb was charged with five offences of aiding and abetting misconduct in a public office.
A 20-year-old soldier from Waterbeach Barracks in Cambridgeshire, was charged with one count of aiding, abetting, counselling and procuring misconduct in a public office.
He was also charged with possession of a Class-A drug.
The 49-year-old reporter and her two alleged contacts were arrested in May and the offices of the Citizen newspaper where she worked were searched.
Two national newspapers were also thought to be involved in the investigation.
Police officers armed with a search warrant examined the newspaper offices, part of Johnston Press publishing group, and seized a number of documents and a computer.
Mother-of-three Murrer was arrested by detectives some time later at her home in Milton Keynes, during a joint operation between Thames Valley Police and Hertfordshire Police.
Detectives told the company they were investigating allegations of “police corruption and the leakage of confidential police information.”
Monday morning officers from Thames Valley Police’s Professional Standards Department charged four people in connection with misconduct in a public office.
A spokesman for Thames Valley Police said the alleged leaks were not connected to the Army or other military information.
All four were released on bail and will appear at Kingston-on-Thames Magistrates’ Court on 15November.
Police later named the 20-year-old soldier as Harry Kearney, thought to be the son of the now ex-Thames Valley Police officer.