The jury in the News Of The World phone-hacking trial heard Thursday that the two highest-profile defendants had a six-year affair.
Rebekah Brooks, former head of Rupert Murdoch's U.K. newspaper business, committed adultery with Andy Coulson, her former deputy at the News of the World and the Prime Minister's former head of communications, it emerged as part of the prosecution's opening statement on Thursday.
Both were married to other people at the time of the affair.
The affair had long been rumored but could only be reported today after the prosecution spoke about it.
The lead prosecution barrister read from a letter from February 2004 found on a computer in Brooks' house where she called Coulson her "best friend".
"The fact is you are my very best friend, I tell you everything, I confide in you, I seek your advice, I love you, care about you, worry about you, we laugh and cry together, " the letter said.
He said the "elegant" letter showed that the affair had been going for at least six years — and that Coulson was trying to break it off at that point.
Edis argued that the affair showed how close the two were over the period when phone hacking took place at the News of the World.
"What Mr Coulson knew, Mrs Brooks knew too," Edis told the jury.
Brooks and Coulson, sitting next to each other in the dock with Brooks' husband Charlie a couple of seats away, sat stony-faced as the prosecution lawyer spoke.
Coulson was appointed to No.10 Downing Street, after stepping down from the News of the World in the light of earlier allegations of phone hacking by journalists at the now-defunct newspaper.
The prosecution argued that both Brooks and Coulson would have had to approve the sums paid to Glenn Mulcaire, who has since been convicted of phone hacking, because cost-cutting at the newspaper during the period covered by the trial meant that all payments over £1,000 ($1,610) had to be approved by one of them. They cited documents showing that the newspaper had considered cutting the amount paid to Mulcaire's agency, before reconsidering.