A dead shark found in Tokyo's Yoyogi Park has sparked an investigation into who brought it there, an officer at Yoyogi Police Station said Monday.

A park security guard called the police at 7 a.m. Sunday after finding the shark, which was covered by a blue tarp and measured about 1½ meters long, the police said.

The shark had been gutted and was found near a parking lot for bicycles near one of the entrances leading to JR Shibuya Station.

"The shark was not rotten, so I guess someone left the shark not so long ago," Hiroshi Okano, a deputy chief at Yoyogi Police Station, told The Japan Times by telephone. He said the police station is keeping its carcass at a storage facility there.

Okano wouldn't disclose any other details because the matter is still under investigation as an illegal dumping case.

On Twitter, dozens of posts from Feb. 14 to early on Feb. 15 said a shark was being exhibited in front of a sushi restaurant in Shibuya. The tweets later said someone had taken it away.

The sushi restaurant, Daidokoroya, said Monday that it could not rule out the possibility that the shark dumped at the park is a salmon shark it bought at Tsukiji fish market on Feb. 14.

Daidokoroya, which initially bought it for consumption at the outlet, said the 102-kg creature was too large to carry into the kitchen. Eventually, at 5 a.m. the next day, it was given to a self-styled artist who wanted to use it for art.

Riki Tamayama, who represents the restaurant, said in a statement that the eatery failed to identify the person.

"All I can do now is to hope that the person who illegally dumped the shark will come out and confess that he did it," Tamayama said.