News International's policy of trawling internal logs for evidence of possible wrongdoing and handing over a succession of Sun journalists to police for questioning is having a "damaging affect on morale and confidence" among the paper's journalists, according to the NUJ.
Crime editor Mike Sullivan, former managing editor Graham Dudman (pictured), ex-deputy editor Fergus Shanahan and head of news Chris Pharo were all questioned for up to 16 hours on Saturday after being arrested by officers from the Met investigating corruption allegations.
The latest arrests came after that of district reporter Jamie Pyatt on suspicion of making illegal payments to police in November and the dismissal of ex-features editor Matt Nixson in July. Nixson is pursing a case for unfair dismissal.
All six have been targeted as a result of information dredged up by News Corp's Management and Standards Committee.
Former Sun editor Rebekah Brooks was arrested and questioned by police in July on suspicion of conspiring to intercept voicemail messages and corruption.
The NUJ's deputy general secretary, Barry Fitzpatrick told Press Gazette: 'This is now extending to The Sun and is no longer only about phone-hacking, it's about anything the company now decides is evidence of unlawful or illegal activity and they are, as far as we know, informing the police without telling their employees.
'They're not NUJ members so it's not that we have a direct interest in that sense, but they are journalists of some considerable standing and it's having a really damaging affect on the morale and confidence of all of the journalists there. Also what it's doing of course is destroying the trust and confidence of the journalists in the current ownership
'The feedback we are getting is they feel they are being basically sacrificed or abandoned in what seems to be an effort by [News International chief executive] Tom Mockridge to prove that he's cleansing the whole operation, but in a way that seemingly pays no regard to the background culture of the tabloid under the current ownership
'There still a lot investigation to be done in terms of not just the phone-hacking but the other practices that are now being alleged. It seems that News International, rather than complete their own investigations first, are simply informing the police."