Head of the Police Federation for England and Wales Paul McKeever has died after suffering an embolism.
Federation chairman Mr McKeever died on Thursday night after being admitted to hospital a few days ago.
Chair-elect of the group Steve Williams said: "I am terribly saddened to announce that Paul McKeever, chairman of the Police Federation of England and Wales, died last night.
"He was admitted to hospital a few days ago and sadly collapsed with a suspected embolism. We await further details. However, my deepest sympathy and that of the entire Police Federation is with his wife and family at this time.
"He was a truly outstanding chairman, and most importantly a truly outstanding police officer and man. A true gentleman, his leadership and reputation will be remembered highly by all those who knew him."
Metropolitan Police Federation chairman John Tully said: "It is with profound sadness that we have today learned of the sudden death of our colleague and National Federation chairman Paul McKeever.
"Paul was a serving Metropolitan officer and was on the verge of retiring from the service after more than 30 years.
"Sincere condolences go to Paul's family, colleagues and friends at this very sad time."