The prosecution in the phone hacking trial has told jurors that e-mail exchanges prove the News of the World was paying public officials for information.
Eight people - including former editors Rebekah Brooks and Andy Coulson - deny a series of charges.
Prosecutors claim that former royal editor Clive Goodman paid for two copies of a Royal telephone directory from palace police officers, with the funds allegedly authorised by Coulson.
A total of 15 copies of the book were found in his home when it was searched in 2006, and of those it is claimed that another two belonged to police but were not necessarily sold by officers, the court heard.
One had an officer’s fingerprint on it while another had an officer’s handwriting on it.
The court heard that on January 24 2003, Goodman emailed Coulson to say: “Andy - one of our royal policemen (St James Palace) has obtained the brand new green book, the telephone directory with all the home numbers of the royal family and their household staff.
“Incredibly useful and he’ll be extremely handy in [the story] tale. The standard price is GBP1,000.”