LONDON — A 400-year-old volume of Shakespeare stolen in England a decade ago and valued US$30 million has been recovered after a man walked into a library in Washington and asked to have it authenticated.

Police in Durham, northeast England, said Friday they had arrested a 51-year-old man over the theft of the First Folio edition of 1623, which scholars consider one of the most important printed books in the English language.

It was among seven centuries-old books and manuscripts stolen in December 1998 from a display case at the Durham University library.

The university said at the time it would be virtually impossible to sell the books to legitimate buyers, and for almost a decade police found no trace of them.

The mystery began to unravel two weeks ago when a man brought the First Folio to Folger Shakespeare Library in Washington, D.C., and asked to have it verified as genuine. Police said the man claimed to be an international businessman who had bought the volume in Cuba.

Staff at the library asked to keep the book while they did research, and discovered it was stolen. They told the FBI, which launched an international search for the man.

Police said the man was arrested Thursday at an address in the English town of Washington, near Durham. He was being questioned Friday while detectives searched his home.

The book remains at the Folger Library, one of the world's leading centres of Shakespearean research. Durham Police said authorities felt would be safer there than in "an FBI warehouse next to piles of cocaine and cannabis.''

Plans were being made to bring the book back to Durham.

American writer Bill Bryson, the university's chancellor, called the recovery "wonderful news.''

"Like Shakespeare himself, this book is a national treasure giving a rare and beautiful snapshot of Britain's incredible literary heritage,'' said Bryson, whose books include "Shakespeare: the World as a Stage.''

The First Folio was published seven years after William Shakespeare's death and was the first collected edition of his plays. Some 750 copies were printed, and about a third have survived, though most are incomplete. Only about 40 complete copies of the book are known to exist, most in museums or public collections.

The stolen copy was acquired by John Cosin, former Bishop of Durham, and was part of the library he established in Durham in 1669. The university said its estimated value, if in perfect condition, was $30 million.

The university hoped to recover the other stolen works, which include a 15th-century manuscript containing a fragment of a poem written by Geoffrey Chaucer, author of "The Canterbury Tales''; an edition of "Beowulf'' printed in 1812; and a book of maps and poetry dating from 1612.

It also promised to keep the First Folio safe.

"Our security has been very significantly reviewed and enhanced to the highest standards since the theft 10 years ago,'' said the university's vice chancellor, Chris Higgins.