LONDON (AFP) - A tiger cub has been born at London Zoo for the first time in 17 years, with the moment captured by hidden cameras, the zoo announced on Wednesday.

Five-year-old Sumatran tiger Melati gave birth to the unnamed cub on September 22 after a six-minute labour. The pregnancy had lasted approximately 105 days.

It was kept a secret by zookeepers who were nervous about the pregnancy.

They kept a close eye on the first-time mother via special cameras so as not to disturb her.

The Sumatran tiger, a subspecies whose natural habitat is the jungles of Sumatra, Indonesia, is now classified as critically endangered on the International Union for Conservation of Nature's red list of threatened species.

The current wild population is estimated at just 300, down from around 1,000 in the 1970s, and the remaining animals are threatened by poachers, habitat loss and human conflict.

"We are simply over the moon about the birth," zookeeper Paul Kybett said.

"We were nervous about the pregnancy, as it was Melati's first cub and we didn't know how she'd react.

"The actual birth happened very quickly and Melati's maternal instincts kicked in immediately as she started licking the cub all over and it soon began wriggling around - we couldn't have asked for a smoother birth!"

The newborn tiger is a direct descendant of the zoo's last cub, Hari, who is the father of Melati.

The cub, whose sex has yet to be determined, will stay out of the public eye "for a few more weeks" in a special cubbing den before visitors are allowed to see it.