Andy Coulson was appointed as editor of News of World in 2003. He resigned from the post in January 2007 after Royal Editor Clive Goodman and private investigator Glenn Mulcaire were convicted.
Goodman and Mulcaire admitted conspiring to intercept communications while Mulcaire also pleaded guilty to five other charges of intercepting voicemail messages.
Following the conviction Coulson said:
Months later, in May 2007, Coulson took up the post of Director of Communications for the Conservative Party. When the coalition was formed after the May 2010 General Election and David Cameron was made Prime Minister, Coulson entered Downing Street as communications chief.
He quit the role in January 2011 after admitting the News of the World phone-hacking row was making his job impossible. He has always denied any knowledge of the practice at the newspaper.
In a resignation statement he said:
Later that year he was arrested in relation to Scotland Yard's long-running investigation into phone-hacking at the News of the World. He was held in July on suspicion of conspiring to intercept communications and corruption and had his bail extended earlier this month.
Earlier today (May 30) Coulson was detained by officers from Strathclyde Police on suspicion of committing perjury during the Tommy Sheridan trial in Glasgow. The 44-year-old gave evidence in Mr Sheridan's perjury trial at the High Court in Glasgow in December 2010.
In Scottish law detention means he will be questioned in custody and then could later be released or arrested.