New York - Monaco’s Prince Pierre Casiraghi was punched in the face during a weekend fight at a New York nightclub that landed a local man in court on assault charges, police said on Monday.

Casiraghi, 24, the grandson of former Hollywood actress Grace Kelly, was briefly hospitalised after the incident, according to media reports. Police said he and three other men were struck by former restaurateur Adam Hock in a dispute at The Double Seven club at around 2am on Saturday.

Among those punched was Stavros Niarchos, the Greek shipping scion and former boyfriend of hotel heiress Paris Hilton, according to a criminal complaint.

Casiraghi told police he was repeatedly struck in the face, according to the criminal complaint, “creating a laceration on informant's cheek, and causing bruising, swelling, redness and substantial pain to informant Casiraghi's face”.

The other three men swore out similar complaints against Hock, 47, whose lawyer said he was simply acting in self-defence.

“An individual now known to me from the criminal complaint as the prince was with others harassing my client and acting like little children, name calling and trying to attack my client,” said Hock's attorney, Sal Strazzullo.

He said Hock was acting in self-defence when he hit the 24-year-old prince and members of his entourage.

“Unless you're a ninja fighter or Bruce Lee, it's pretty tough to defend yourself against four men,” Strazzullo said.

Hock was released from Manhattan Criminal Court without bail after he pleaded not guilty to four counts of assault, he said.

Police declined to comment on whether the four men suffered injuries, saying only that “each was struck in the face with a closed fist”.

There was no immediate response to calls placed to an attorney for Casiraghi, who lives in Italy and is third in line to the throne of Monaco. He is the son of Princess of Caroline of Monaco and her second husband, who was killed in a boating accident when Pierre Casiraghi was a young child. - Reuters