The escapee, a one-year-old Humboldt penguin, was spotted swimming in a river mouth in the Japanese capital.

An official from the harbour-front aquarium said the bird appeared to have scaled a wall in its bid for freedom.

The Humboldt penguin hatched last January and lives with 134 penguins in an enclosure at Tokyo Sea Life Park.

“We first noticed the penguin might have fled when the director of a neighbouring zoo e-mailed us Sunday with a photo,” park official Takashi Sugino told AFP news agency.

He said officials were struggling to recapture it because it swam “at a tremendous speed”.

via BBC News – Tokyo search for young penguin escapee.