The Enquirer's reward has posed troubling questions: Does it undermine the credibility of the government witness by allowing the defense to argue, as it has, that he was motivated by financial gain? And does it encourage crime witnesses to hold out for the biggest payday before cooperating with authorities? Those are issues The Enquirer's editor in chief, Steve Coz, said he considered before offering the reward as well as the publicity and additional scoops it would generate.

Mr. Coz said the reward was first suggested by Bill Cosby himself, and The Enquirer posted it because of a cooperative relationship it had with the entertainer over the years. David Brokaw, a spokesman for the Cosby family, confirmed the relationship but said relations soured after a subsequent story about Mrs. Cosby's reaction to her son's death.

Mr. Coz said the police and prosecutors supported the reward. While recognizing the potential inducement for embellishment, Mr. Coz said that the police investigation backed up Mr. So's tip and that he did not think the reward offer would have a longer-lasting negative impact on the justice system.

''You kind of have to look at justice as something that always manages to rise to the top, through police work, through The Enquirer,'' Mr. Coz said. ''Justice always seems to prevail in these cases.''

Not that the tabloid's sleuthing has earned the media any appreciation from the courts or the prosecutors in the Cosby matter. Judges have gone to extraordinary lengths to keep the press at bay. Rather than following the usual practice of holding a public preliminary hearing to determine whether Mr. Markhasev should be bound over for trial, prosecutors presented the case to a grand jury convened in private, and transcripts of the sessions were ordered sealed. A gag order has been imposed on all lawyers and parties in the case, and television and still cameras have been banned from the courtroom.