By Phil Vinter PUBLISHED: 04:42 EST, 11 July 2012 | UPDATED: 02:02 EST, 12 July 2012 Just six after Japan celebrated the birth of its first panda bear in 24 years the newborn cub has died. The young bear is thought to have developed pneumonia and was discovered on its back lying on its mother's chest at Ueno Zoo in Tokyo. It was the first time the zoo's natural breeding programme had led to a birth, and heartwarming photos of proud mother Shin Shin cuddling her new baby had been shown around the world. Scroll down for video Tragic: Just six after Japan celebrated the birth of its first panda bear in 24 years the newborn cub has been found dead
@highlight
Dead male cub found by zookeepers lying on its back on its mother's chest
@highlight
Seven-year-old Shin Shin gave birth just days after being declared pregnant
@highlight
Baby had been kept in an incubator earlier this week but had been returned to its mother on Tuesday
@highlight
Baby's mother and father are on loan from China and will eventually be returned
‘No matter what names the Japanese side gives, it cannot change the fact that the two pandas belong to @placeholder.