Computers seized during a police search of Rebekah Brooks's office at News International did not appear to have been used by her, the phone hacking trial heard today.

Five hours after Mrs Brooks resigned as chief executive of the newspaper group on July 15 2011, detectives carried out an agreed search of her office at Thomas More Square, Wapping. They retrieved two iPads, an Apple Mac computer and an HP computer.

However, Detective Constable Alan Pritchard told the court that when digital forensics firm Stroz Friedberg analysed the machines they could not find evidence of "user activity" by Mrs Brooks.

The police officer with Operation Weeting was seeking to justify why the police had sought a search warrant from Westminster Magistrates Court for an early morning raid on Mrs Brooks’s and her husband Charlie's Oxfordshire home which took place on 13 March 2012.

Jonathan Laidlaw, for Mrs Brooks, suggested that the 5am raid had been unnecessary since the police had recovered her computers during the search of her office at Wapping and that her solicitors, Kingsley Napley, had told police that she would voluntarily attend any interview and provide any documents they wanted to inspect.

Det Const Pritchard replied that the withdrawal of material from News International's archives and the hiding of evidence below the Brooks's flat at Chelsea Harbour in July 2011 meant there were reasonable grounds for the warrant application.

On the issue of Mrs Brooks's computers, he told the Old Bailey that analysis of the "user activity" on the machines indicated that "she wasn't using them at the time."

Detective Inspector Steven McCabe, investigating officer in the inquiry into the alleged hiding of evidence, denied that the 5am raid in 2012 had been staged to humiliate the Brooks's.

He agreed with Jonathan Laidlaw QC, for Mrs Brooks, that with hindsight the police could have included Mrs Brooks's offer to co-operate in the warrant application.

He said: "Having some information in there would not have harmed the application, but I firmly believe a full comprehensive picture had been put into the application."

Det Insp McCabe said the police had arrived so early at the Brooks's home at Jubilee Barn because the raid was part of a series of arrests in several counties that were co-ordinated so that the suspects would not tip each other off and that "no material could be destroyed or hidden."

He added that he was also aware that racehorse trainer Mr Brooks was intending to attend Cheltenham races later that day.

In answer to Mr Laidlaw, Det Insp McCabe said he was aware that Mrs Brooks's new baby, Scarlett, was likely to be at the home but did not know that she had been born prematurely and that Mrs Brooks was likely to be anxious about her.

Asked by Mr Laidlaw: "Would you have expected the child's Moses basket to be searched?", Det Insp McCabe replied: "Yes."

Had the search had been carried out "merely to humiliate and embarrass?", Mr Laidlaw asked.

The officer replied: "I'm not in the business of humiliating anyone."

Mrs Brooks and Mr Brooks deny conspiracy to pervert the course of justice.

The case continues.