Britain's best-selling newspaper may become embroiled in the phone- hacking cases announced this week.
In a potential public relations setback for Rupert Murdoch's News International, one of the charges against his former protégé Rebekah Brooks covers the period when she was editing The Sun.
Mrs Brooks, a former editor of the News of the World, ex-news editor Greg Miskiw and Glenn Mulcaire, a private detective, are charged with plotting to hack the phone of the trade union leader Andy Gilchrist. The period covered by the charges is 3 December 2002 to 22 January 2003.
Mrs Brooks was promoted to the helm of The Sun in early 2003 and her first day as editor of the daily paper was 14 January that year. Six days later, The Sun published a story about the private life of Mr Gilchrist who, as general secretary of the Fire Brigades Union, was leading a national strike.
The charging period raises the prospect that The Sun will form part of the proceedings when the case comes to trial next year. Mrs Brooks, who denies all charges against her, is due to appear at Westminster Magistrates Court next month in a preliminary hearing to answer phone-hacking charges. She is among seven former NOTW journalists charged with conspiracy to intercept the communications of 600 people. With Mr Mulcaire, the journalists are also charged with plotting to hack the phones of named individuals, such as Mr Gilchrist.
Mrs Brooks, a former close friend of Mr Murdoch and David Cameron, is also charged with three counts of conspiracy to pervert the course of justice over the Scotland Yard inquiry into phone hacking. A hearing in that case is due in September. When those charges were brought in May, Mrs Brooks labelled the investigation a "waste of public money".
She said in a statement on Tuesday: "I did not authorise, nor was I aware of, phone hacking under my editorship."
News International said it would be inappropriate to comment on "active proceedings".