Rebekah Brooks was involved in a deliberate effort to hide material from police during the "panic-stricken" days around the closure of the News of the World, the jury in the phone-hacking trial has been told.

Brooks, then chief executive of News of the World publisher News International, and her personal assistant Cheryl Carter have been accused of trying to conceal seven boxes of her notebooks the day after the announcement that the paper was to close down and two days before its final edition. They deny the charges.

Andrew Edis QC, for the prosecution, told the jury on Monday the attempt to hide evidence happened during the "fevered" and "anxious" days before the paper was closed in early July 2011.

Edis said Brooks was aware Scotland Yard had reopened its investigation into phone hacking in January 2011 and had declared the company's determination to co-operate with the police.

"There was always a course of justice in existence which could be perverted by hiding evidence. Hiding evidence was not acceptable at any time that year, but the atmosphere, we would suggest, became even more fevered as time went on," said Edis.

On 7 July 2011 it was announced that the News of the World was to close. On 8 July Carter arranged to have the boxes containing Brooks's notebooks removed from the News International archive in Enfield, the jury was told.

This day, said Edis, was a "significant day" as it was the day that the former editor of the News of the World, Andy Coulson, was arrested.

"A media firestorm which was about to engulf the News of the World, so you can imagine the extremely anxious if not panic-stricken approach that must have been going on," Edis told the jury.

"When we come to look at what Mrs Brooks was doing in July 2011, we always need to bear in mind the context. This was a big business for News International and for her. At all times she was aware there was a police inquiry, Operation Weeting," he added.

Phone-hacking trial: Cheryl Carter arrives at the Old Bailey. Photograph: Barcroft Media

The jury heard how Carter, along with her son Nick and Gary Keegan, the husband of Brooks's other personal assistant Deborah Keegan, went to Enfield to collect seven boxes of notebooks and took them to Carter's home.

They were told they were selected for this exercise two days before the News of the World was to close because they could be trusted.

Later, in an interview with police under caution, Carter said the boxes had in fact been mislabelled and contained her own notebooks, the prosecution said.

The boxes of notebooks have never been found, Edis added.

Carter was also alleged to have given a false alibi to the police about the whereabouts of Brooks on the same day claiming she was not in the office, when mobile phone records show that the two of them had been at News International's Wapping headquarters.

"The false alibi was quite dishonest to cover what happened. Because she'd remember where the boss was on the Friday before the News of the World closed, wouldn't she?" said Edis.

He claimed that Carter not only lied about the contents of the boxes but also about the reasons for removing them.

Carter said when she was being questioned by police the reason why the boxes were removed was because Ian Mayes, the News International archivist, had asked her to move them because the archive was downsizing. Edis told the jury that was simply not true.

"So there were a number of falsehoods about this exercise all of which were completely unnecessary if they related to material related to Mrs Carter, not Mrs Brooks," said Edis.

Brooks ordered deletion of emails, court told

Edis also alleged that Brooks ordered the deletion of emails that covered the entire period of her editorship of the News of the World and the Sun.

It was "normal policy" for companies to have email deletion policies to improve efficiency. "There's nothing wrong with that in principle," he said, and News International's original plan was to delete everything "before December 2008".

But by looking at "Mrs Brooks's personal involvement" in the email deletion, "we may learn what she hoped it might achieve for her", he said.

In January 2010 Brooks sent an email to News International's legal affairs department asking: "What happens to my emails with deletion?"

In June she inquired why the deletion programme was not already under way. "That's her chasing the implementation of the email deletion," said Edis.

Then in August 2010 she sent another email reiterating that everyone needed to know that "anything before January 2010 will not be kept". When that date of January 2010 was queried, she replied: "Yes. January 2010. Clean sweep, Thanks."

Edis said: "So there's a change in the date. Now it is anything before January 2010. Which happens to catch her entire time as a working editor at News International."

On the changing of the email deletion date, Edis said: "We suggest that shows Mrs Brooks may have had a personal interest in this email deletion policy – both to the date of the cut-off and for her own personal emails – also that it should be got on with.

"This is all going on in the context of the Guardian having published its article in the summer of 2009.

"We suggest that there is some evidence that Mrs Brooks was keen to get rid of the material that related to her activities when she was editor, first of the News of the World and then of the Sun."

Vince Cable: Brooks voiced concerns his stance on News Corp's BSkyB takeover. Photograph: Stefan Rousseau/PA

The jury was also shown an exchange of emails dating back to December 2010 between Brooks and Matthew Anderson, News International's head of corporate affairs.

Brooks emailed Anderson about her concerns that Vince Cable, the business secretary, would not change his view on News International parent company News Corporation's bid to take full control of BSkyB.

In an email dated 16 December 2010, she protested that the Financial Times was "attacking News International because News Corporation are trying to buy Sky", adding: "It's not going to change Cable's view of us."

Anderson replied by saying he was confident that they could put some distance between the company and the phone hacking days of the past. "What we lose by not putting out a statement is credibility. We have spent months moving from rogue reporter to zero tolerance with some success," he wrote.

Five days later, on 21 December 2011, Cable was stripped of responsibility for ruling on News Corp's Sky takeover after telling undercover Daily Telegraph reporters he was "at war" with Rupert Murdoch.

The trial continues.