London (CNN) -- Four people -- two former police officers, a former prison officer and a public official -- pleaded guilty in a London court Friday to charges of misconduct in a public office.
The charges at the Old Bailey Criminal Court follow an investigation into corrupt payments by British newspapers.
Former police officer Alan Tierney, who pleaded guilty to two charges of misconduct in public office, admitted selling information to The Sun newspaper.
Ex-prison officer Richard Trunkfield also admitted selling details to The Sun, relating to a "high-profile" prisoner.
The Sun, Britain's best-selling tabloid, belongs to the UK arm of Rupert Murdoch's News Corp. media empire.