Neville Thurlbeck has become a key figure in the scandal because he appears to be named in a crucial piece of evidence that critics of the company have seized on as proof the problem is widespread.

The evidence — an email addressed ‘for Neville’ — included the transcripts of voicemail messages and resulted in James Murdoch agreeing to make a payout of around 750,000 sterling ($1.2 million) to an early hacking victim, the soccer union boss Gordon Taylor.

Critics of the company have said the much larger than normal payout was intended to buy the victim’s silence and prevent the scale of the problem from being made public because Taylor had secured a copy of the email.

However, James Murdoch has consistently argued he was not made aware of the relevance of the email and said he simply followed legal advice in agreeing to the payout.

News Corp’s British newspaper arm News International had long argued that the hacking of phones to secure stories was carried out by one rogue reporter, Clive Goodman, with the help of private investigator Glenn Mulcaire. That defence crumbled earlier this year under a host of disclosures.

“Murdoch had been kept in the dark and deprived of vital evidence showing phone hacking went far wider than the Goodman/Mulcaire issue,” Thurlbeck said in a statement to Reuters.