The UK publishing arm of Rupert Murdoch's News Corp deleted 20 million emails in 2010 and 2011 as investigations into illegal phone hacking by journalists gathered pace, according to new evidence in a lawsuit that could cast a shadow on the takeover of pay TV provider Sky .

News Group Newspapers is being sued by a group that includes television stars and a former professional soccer player. At a pre-trial hearing on Thursday in London, lawyers for the victims cited new evidence from a statement provided by one of the company's IT managers.

Could the phone hacking scandal throw another spanner in the works for Rupert Murdoch and his son James' pursuit of Sky? Credit:AP

The manager testified that millions of messages were erased because of problems with the IT system, the victims' lawyer David Sherborne said.

"Our case is that it was deliberately ordered by those at the top of the tree as a way of getting rid of incriminating emails," he said. "They were continuing their mass destruction of emails even after the police had started their investigation."