Los Angeles- In a case full of intrigue, it coulda been a contender for biggest mystery.

Tucked inside last week’s federal grand jury indictment of gumshoe-to-the-stars Anthony Pellicano was an allegation that one of the private eye’s associates illegally tried to access personal phone records for one “Johnny Friendly.”

Authorities said the pseudonym referred to a victim who was cooperating with the investigation. That led to speculation that it was a big name in Hollywood.

Turns out, it was: Sylvester Stallone, according to people familiar with the case.

As any cineaste knows, Johnny Friendly was the crooked union boss played by Lee J. Cobb in Elia Kazan’s 1954 classic “On the Waterfront.” In the movie, Friendly is the nemesis of Terry Malloy, the broken-down boxer with “a one-way ticket to Palookaville” played by Marlon Brando.

In real life, Stallone – whose big break came playing palooka Rocky Balboa – is known to sometimes use the “Johnny Friendly” moniker when trying to travel incognito.

The indictment says the Pellicano associate sought to access a proprietary SBC telephone database in February 2002 “to obtain telephone information regarding ‘Johnny Friendly.’ ”

Stallone is listed elsewhere in the indictment, under his real name, as having been a wiretap victim that month. At the time, Stallone was embroiled in a lawsuit with a former business manager represented by entertainment lawyer Bert Fields, who has publicly said he is a “subject” in the Pellicano case.

Thom Mrozek, a spokesman for the U.S. attorney’s office, would not reveal the identity of Friendly, other than to reiterate that it is a pseudonym.

Likewise, Stallone’s spokeswoman, Michelle Bega, would shed no light on the case of Johnny Friendly. “We have no comment,” she said.