LONDON — The poet W.H. Auden was suspected by MI5 of playing a part in the escape to Moscow of the British spies Guy Burgess and Donald Maclean.

Auden, whose centenary is being celebrated this year, had known Burgess for 20 years, since they were at Cambridge together, and he had been at school with Maclean.

His fellow poet Stephen Spender disclosed that Burgess telephoned him at his London flat the day before he fled the country, anxiously trying to get hold of Auden, who had a home on the island of Ischia near Naples.

MI5 files declassified Friday show that Auden denied all knowledge of the call, even though he had been staying with Spender at the time.

Spender insisted he passed on the message and that Auden replied: “He must be drunk.”

Auden returned to Italy that weekend, while Burgess and Maclean fled aboard a cross-channel ferry, on Saturday May 25, 1951.

They had been tipped off by fellow Soviet double agent Kim Philby — who was working for MI6 in Washington — that Maclean was about to be unmasked as a Russian spy.

The Security Service was under intense pressure from the FBI as the spy scandal unfolded and evidence of Burgess’s homosexual connections emerged.

MI5’s representative in Washington sent a telegram to London saying: “The FBI particularly want results of Auden and Philby interview. I think the FBI will be satisfied with interim reply as long as we hand over something.”

But at the end of June, MI5’s director general, Sir Percy Sillitoe, replied: “Although Spender and Auden have been interviewed by the Italian police, we have not ourselves had the opportunity of interrogating them.”

The Italians said Auden arrived back in Ischia on Monday, May 28. He denied all knowledge of the call by Burgess to Spender the previous Friday but said he had invited Burgess to stay in Italy during the summer.

The Americans questioned the writer Christopher Isherwood, who moved in the same circles as Auden and Burgess.

Isherwood was anxious to play down his own connections with Burgess, whom he described as “a very heavy drinker, an emotional person, and likely a homosexual.”

But the FBI added in its report: “He did remember that one Tony Blunt [probably Anthony Blunt] … knew Burgess better than anyone.”

It was one of a series of clues in the file that Blunt was embarrassingly close to the traitors, yet he was not unmasked as the fourth man for another 10 years.