Yoko Ono's chauffeur has been charged with first-degree attempted grand larceny and has been bailed for $500,000 (£255,000).
Ono was married to John Lennon for 11 years before his murder
Koral Karsan, 50, from New York, allegedly blackmailed Ono by saying he would release photos and audio tapes of her unless she paid him $2m (£1.02m).
Prosecutor Maureen O'Connor requested a high bail, contesting "there is no doubt that he would flee".
Mr Karsan's lawyer says he will "vigorously dispute" the charges.
He also talked about killing her and her son Sean in a conversation which was recorded by investigators, police said.
The Turkish-born chauffeur had worked for Ono for six years, driving her on an almost daily basis when she was in New York.
Lennon and Ono staged a "bed-in" for world peace in 1969
Karsan's alleged blackmail attempt is said to have taken place last week, on the 26th anniversary of the murder of Ono's husband, John Lennon.
Ono's security staff say Karsan dropped off a letter and a photograph of Ono in nightclothes to the artist's apartment in New York, where she once lived with the former Beatle.
Staff told detectives that in his "rambling" note, Karsan claimed to have secretly photographed Ono and made recordings of her private conversations - apparently while she was in the car with him.
The driver warned he would make the material public if she did not pay him, police said.
"You're reminded that this takes place around that time of the anniversary, when she is in a particularly vulnerable position," Mintz said.
"It just adds insult to injury. This one's really cold."
Ono and Lennon married in 1969 after the singer left his previous wife, Cynthia.
They recorded together throughout the 1970s, and became notorious for their anti-war stance.
But in 1980, shortly after his Double Fantasy album went to number one around the world, Lennon was shot dead by Mark Chapman outside his New York apartment.
Fans observe the anniversary of his death by gathering at Strawberry Fields, a section of Central Park opposite the Dakota apartment building.