Former News International chief executive Rebekah Brooks and ex-News Of The World editor Andy Coulson had a long-standing secret affair lasting at least six years, jurors in the phone hacking trial have heard.
Prosecutor Andrew Edis QC told the Old Bailey that in February 2004, when the pair were both working at the media giant, they had been having a relationship for some years.
He said during the police investigation into the hacking of murdered schoolgirl Milly Dowler's phone, a letter was found on Brooks' computer to Coulson from February 2004, that made the relationship clear.
Mr Edis said: "The point that I'm going to make in relation to that letter is that over the relevant period, what Mr Coulson knew, Mrs Brooks knew too. And what Mrs Brooks knew, Mr Coulson knew too - that's the point.
The court heard the pair had been having an affair dating back to around 1998, spanning the period covered by their phone hacking conspiracy charge.