Former News of the World editor Rebekah Brooks has been formally found not guilty of one charge of misconduct in a public office.
However, jurors at the phone-hacking trial will still decide whether Ms Brooks, 45, is guilty of four further offences.
She faces one charge of conspiring to hack phones, two of perverting the course of justice, and one of conspiring to commit misconduct in a public office.
Judge Mr Justice Saunders, sitting at the Old Bailey, instructed the jury to formally acquit Ms Brooks on one of the charges.
It relates to an allegation that she sanctioned a payment of £4,000 to a public official for a picture of Prince William dressed as a bikini-clad Bond girl at a Sandhurst party.
The image was not published, though it led to an exclusive in The Sun in September 2006 with the headline "Willy in a Bikini". The story was accompanied with a mocked-up picture of the prince wearing a green swimsuit and Hawaiian-style flowers.
Ms Brooks edited The Sun before taking the helm at its sister paper.
The judge said: "I have decided that there is no case for Ms Brooks to answer on count four.
"That is the charge relating to a picture of Prince William in a bikini.
"Whether or not there is a case to answer is for me to decide."
Ms Brooks stood and smiled as the jury foreman recorded a not guilty verdict.
She was then sworn into the witness box.
She confirmed she was born in Warrington, Cheshire, in 1968 and was an only child.