Two days after Bill Cosby’s only son was slain, a woman claiming to be the entertainer’s illegitimate daughter was arrested in an unrelated attempt to extort $40 million, federal prosecutors said Monday.

Meanwhile, police in California located two possible witnesses to the killing of Ennis Cosby on Monday and turned them over to investigators for questioning.

Autumn Jackson, 22, demanded the money to keep from going to a tabloid. She and Jose Medina, 54, who was to write her story, were arrested Saturday at a New York law firm representing Cosby after signing a purported $24 million settlement to “end everything,” said U.S. Attorney Mary Jo White.

According to an FBI affidavit, the family of Bill Cosby apparently had made payments to Autumn Jackson for educational purposes for several years, as he does for numerous other young people in need of assistance.

A family spokesman said Cosby has a birth certificate proving the woman is not his daughter.

Jackson and Medina were scheduled to appear at hearing today in federal court. If convicted of extortion, they each face up to five years in prison and a $250,000 fine.

Even though both suspects in the extortion case were identified as being from Southern California, authorities say it appears unrelated to last Thursday’s shooting death of Cosby’s 27-year-old son in Los Angeles.

“There is no evidence that extortion scheme is connected with the death of Ennis Cosby,” White said.

Also Monday, police in the Los Angeles suburb of Torrance picked up two witnesses at a drug store and turned them over to LAPD investigators. KCBS-TV said police went to the drug store after a neighbor reported seeing a blue hatchback that appeared to match one driven by the witness shown in the sketch.

Police emphasized the witnesses were not suspects, and wouldn’t say whether they matched the sketches or the information about the car.

“The most I can tell you at this point in time is they are being identified as witnesses,” said Torrance Police Lt. Steve Gilliam.

Meanwhile, the tabloids, encouraged by Cosby, have launched a bidding war: The Globe announced a $200,000 reward to top the National Enquirer’s $100,000 offer for information leading to an arrest and conviction.

Already, more than 200 calls have come in to a police hot line after the release of a sketch of a suspect in the slaying of Cosby, a graduate student gunned down as he changed a flat tire.