A Scotland Yard officer has been reprimanded after a document detailing Home Secretary Theresa May's personal engagements was left lying around following an event.
The officer was subject to "local management action" but was not suspended after the weekly diary was left at a Glasgow concert hall on Sunday, a Metropolitan Police spokeswoman said.
It comes after Britain's biggest force launched an inquiry into how the weekly diary went missing, but insisted that security was not compromised.
A Scotland Yard spokeswoman said: "Following an investigation, and as part of the MPS misconduct process, an officer has been subject to local management action."
She added: "The paper was not protectively marked. Security was not compromised."
It is understood the diary was left at Glasgow Concert Halls on Sunday where Mrs May was attending the National Police Memorial Day to remember fallen officers, which was also attended by the Prince of Wales.
The five-page document was found by Royston Martis, deputy editor of the Police Review magazine, at 5.30pm, after the Home Secretary and her security team had left the event.
It has been returned to the Home Office and no details of specific events were published until after they had taken place.
Keith Vaz, Labour chairman of the Commons Home Affairs Select Committee, said: "It's serious that someone with the security importance of the Home Secretary should have her security compromised in this way.
"It is very disappointing that this has happened."
The diary included a Tuesday morning meeting with Keith Bristow, Chief Constable of Warwickshire Police, who was described in the document as an "NCA (National Crime Agency) candidate" as the Home Office is looking to appoint the agency's chief, according to Police Review.
Mrs May also held a 30-minute "private meeting" with Strathclyde Chief Constable Stephen House, an unsuccessful applicant for the Scotland Yard Commissioner's job, as well as meetings with the National Security Council and Deputy Prime Minister Nick Clegg in his office later in the week.
The document also recorded at what time and on which days Mrs May would be going to the gym in her Maidenhead, Berkshire, constituency, the magazine said.
Detailed timings and addresses for events Mrs May was to attend in the Maidenhead area, including the opening of Chissock Woodcraft, near Reading, and a charity cabaret evening at Wentworth Golf Club, were also given, along with mobile telephone numbers for Mrs May's private secretary and key contacts at the events.
The words "News of the World", the newspaper axed in the wake of the phone hacking scandal, were also scribbled in black pen on its front page.