A body found on a Brooklyn beach earlier this week had feet that were encased in hardened concrete, according to NYPD detectives.

"Cement shoes" as they are known, have long been associated with organised crime and the Mafia, but mostly in fictional depictions.

Several crime writers have said they believe this to be the first time they have actually been used in a murder.

The victim, identified as Peter Martinez, 28, was a known gang member.

"This individual was wrapped in plastic bags and his arms were tied behind him and his feet were submerged in concrete," Detective Robert Boyce said in a press conference.

"Obviously a homicide," he added.

Although rumours abound of mobsters and murderers hiding their victims at the bottom of the ocean using "cement shoes", very few real-world examples have been proven to exist.

In August 1964 the body of Ernest Rupolo was found in New York's Jamaica Bay with two concrete blocks tied to his legs.

But feet encased in concrete has always been considered the stuff of legend - and fiction.

In the opening pages of 1989 novel "Billy Bathgate" a character "delicately, gingerly, placed one foot at a time in the laundry tub in front of him that was filled with wet cement".

Investigators from New York's Office of the Medical Examiner are still working to determine the cause of death, and if the cement was affixed to Martinez's body before or after his death.

But whoever did it failed to wait for the cement to fully dry. It was filled with air bubbles, which may have been what caused the body to come ashore.