Rupert Murdoch is expected to fly to London this week after reassuring staff he would not sell The Sun in the wake of a second wave of arrests at the newspaper.
Five senior journalists were among eight people arrested over allegations of improper payments to police and public officials.
It is expected Mr Murdoch, chairman and chief executive of News Corporation, will visit staff in London towards the end of the week to deal with the latest crisis to rock one of his British newspapers.
National Union of Journalists general secretary Michelle Stanistreet said: “Journalists are reeling at seeing five more of their colleagues thrown to the wolves in what many sense to be a witch-hunt.”
She added: “Once again Rupert Murdoch is trying to pin the blame on individual journalists hoping that a few scalps will salvage his corporate reputation.”
Tom Watson MP, who sits on the Culture, Media and Sport Select Committee, told Channel 4 News that News International bosses may be called back to give further evidence to the committee.
“If they’ve got evidence that shows that in fact there is a reasonable suspicion that police were paid by News International then Parliament needs to know about it.”
Watch: Interview with Tom Watson
A serving officer in Surrey Police, a Ministry of Defence employee and a serving officer in the Armed Forces were also detained by officers from Operation Elveden.
The operation has widened to include suspected corruption involving public officials as well as police officers. Operation Elveden – which runs alongside the Met’s Operation Weeting team – was launched as the phone-hacking scandal erupted last July with allegations about the now-defunct News of the World targeting Milly Dowler’s mobile phone.
The arrests of deputy editor Geoff Webster, picture editor John Edwards, chief reporter John Kay, chief foreign correspondent Nick Parker, and John Sturgis, who is a news editor, sparked speculation that the red top would go the same way as the News of the World.
They followed the arrests two weeks ago of four current and former Sun employees, as well as a police officer.
However, a leaked memo from Tom Mockridge, chief executive of News International – part of News Corp – to staff said that Mr Murdoch had personally assured him of his “total commitment to continue to own and publish” the paper.