LONDON - British intelligence was unable to find any trace of Charlie Chaplin’s birth when it investigated allegations that he had communist sympathies, newly released files showed on Friday.

The mystery of the film star’s birth emerged when US authorities asked MI5, Britain’s domestic spy agency, to look into his background after he left the United States in 1952 under a cloud of suspicion over his communist links.

British intelligence could find no confirmation that Chaplin was born in London in April 1889, but dismissed claims that he was in fact originally from France.

The actor was believed to have been born on April 16, 1889 in East Street, Walworth, south London — ironically just four days before the birth of Nazi leader Adolf Hitler, whom he lampooned in his classic 1940 film “The Great Dictator”.

MI5 searched through files in London for his birth certificate, including checks for his supposed alias “Israel Thornstein”.

But the previously secret records show that agents concluded: “It would seem that Chaplin was either not born in this country or that his name at birth was other than those mentioned.”

John Marriott, then head of MI5’s counter-subversion branch, was not convinced that the absence of a birth certificate was a matter of concern for the intelligence services.

He wrote: “It is curious that we can find no record of Chaplin’s birth, but I scarcely think that this is of any security significance.”

Police investigators from Scotland Yard’s Special Branch added to the intrigue by passing on a tip-off from a source who claimed the actor was born near Fontainebleau, south of Paris.

A police memo to MI5 noted: “There may or may not be some truth in this, but in view of the fact that no documentary proof has been obtained that Chaplin was born in the United Kingdom, it may well be that he was in fact born in France.”

The case was handed over to MI6, Britain’s foreign intelligence service, but it found no trace of Chaplin’s birth in either Fontainebleau or nearby Melun.

Chaplin’s previously secret MI5 files show that security officials were concerned about whether to advise prominent figures in Britain to avoid meeting the comic actor.

In the early 1950s, Washington was in the grip of McCarthyist paranoia about Soviet infiltration. A telegram sent to MI5’s liaison officer in Washington in October 1952 pleaded: “We have very little information on which to guide any highly placed persons likely (to) encounter Chaplin during his visit here. Can you help?”

The reply, which was copied to MI5 director general Sir Percy Sillitoe, noted tersely: “Chaplin has given funds to communist front organisations. Understand US government cannot prove party membership.

“He has been involved in paternity and abortion cases. Being an alien, Immigration can exclude him for moral turpitude.”