US police on Saturday arrested a man whom they expect to charge with the murder of reputed New York mafia boss Francesco "Frank" Cali.

The purported head of the Gambino crime family, also known as "Franky Boy," was shot repeatedly outside his home in the New York borough of Staten Island late Wednesday.

Anthony Comello, 24, was taken into custody in neighboring New Jersey, apparently without incident, and had not yet been returned to New York, a New York Police Department official told AFP, on the condition of anonymity.

"We are very confident that he will be charged with the murder of Mr Cali," upon the suspect's handing over to New York, the official said.

US media reported that Cali's killing marked the first murder of a New York mob chieftain in 34 years since the death of Paul Castellano -- another Gambino family boss -- by order of John Gotti, who was known as Teflon Don.

The motive for Cali's murder is not clear, the police official told AFP, adding that the murder weapon has not yet been recovered.

"The investigation is still very, very young," the official said. "Obviously, there are multiple angles that are being explored at this time."

Comello has numerous addresses, including on Staten Island, the official said.

Cali, 53, had deep ties to Sicilian organized crime factions and is thought to have been leading the Gambinos since 2015. He purportedly wielded influence both in the United States and in Italy.

Cali shunned the limelight even after becoming don, ruling from the top while lying low in his affluent Staten Island district, where Castellano also held court.

The Gambino family is one of New York's five historic Italian Mafia families -- along with the Genoveses, Luccheses, Colombos and Bonannos.

Last October, 71-year-old Sylvester Zottola of the Bonanno family was shot dead while waiting in his car for an order from a McDonald's in New York's Bronx borough.

His son, Salvatore, was shot three months earlier outside the family home, but survived.

Asked whether Comello has any organized crime connections, the police official told AFP: "Right now there's no information to support that he has any ties."

After Gotti died in prison in 2002 the mob's influence on the US eastern seaboard waned, but Cali's murder put it back in the headlines.

"We thought those days were over," the city's Mayor Bill de Blasio told journalists after the shooting. "But I guess old habits die hard."