Culture Secretary Jeremy Hunt's former special adviser Adam Smith will give evidence to the Leveson Inquiry next week, it was announced today.
News Corporation lobbyist Frederic Michel will also appear on the same day.
Mr Smith resigned last month over his dealings with Mr Michel in relation to the BSkyB takeover bid.
Their evidence on Thursday will lead to fresh scrutiny of Mr Hunt's role in the process.
Also appearing at Leveson next week will be former Labour Cabinet ministers Lord Mandelson, Lord Reid, Tessa Jowell and Alan Johnson.
Labour MP Tom Watson, who has been one of News International's fiercest critics and helped uncover the phone hacking scandal, will also give evidence, as will television journalists Jeremy Paxman and Andrew Marr.
Mr Smith resigned after the release of a raft of emails indicating that contacts between News Corporation and Mr Hunt's office went much further than previously thought.
The adviser admitted that his contacts with Mr Michel "went too far" and created an impression that relations between the Department for Culture, Media and Sport and News Corporation were "too close".
Mr Smith insisted the "content and extent" of his contact with Mr Michel had not been authorised by Mr Hunt, who has faced calls to resign himself over the issue.
Mr Hunt is still awaiting a date to appear before Leveson, to give his own account of events.