LONDON — The suspects include a flamboyant pop star, a sharp-tongued comedian, a disc jockey known as “the hairy cornflake” and a quirky Australian-born entertainer who performed at the queen’s diamond jubilee concert. Most are in their 70s or 80s, and most are, or were, household names — celebrities from a bygone era.

All have been caught up in what surely qualifies as one of the more ambitious, and possibly quixotic, law enforcement investigations in Britain in recent years: Operation Yewtree, a nationwide inquiry into sexual offenses that may or may not have been committed decades ago. In American terms, it is as if Captain Kangaroo, Dick Clark and Jerry Lewis were suddenly being accused of committing sexual crimes dating back 30 or 40 years.

Yewtree was formed in response to the disclosures last year that the entertainer Jimmy Savile had been a serial sexual predator with scores of victims, many of them under age, in an entertainment career spanning four decades. The case, the authorities say, spurred hundreds of people to come forward with their own accounts of being sexually assaulted as teenagers — in some instances, they said, at the hands of Savile-esque celebrities during a time when such men seemed to all but help themselves to girls they came in contact with.