They're a shy, rare bird breed, the size of a chicken - and hunting them is officially banned in Pakistan. But it is no holds barred when Arab royals begin their Houbara bustard hunting trips.

Arab princes and their wealthy friends like to hunt Houbara bustards both as a sport and because the meat is considered an aphrodisiac.

The birds migrate in the thousands from Central Asia to Pakistan every winter - giving the Pakistani elite a chance to engage in "soft diplomacy".

Despite the hunting ban, the government issues between 25 and 35 special permits annually to wealthy sheikhs, allowing them to hunt the bird in its winter habitat.

The hunts are secretive, but controversial.

Image captionA sheikh and part of his entourage at a bustard hunt in 2015

The hunting parties are given a limit of 100 birds in a maximum 10-day period, but often exceed their quota.

In 2014, the leaking of an official report that a Saudi prince had killed more than 2,000 birds in a 21-day hunting safari sparked an outcry.

The government imposed a "temporary moratorium" on hunting, but quietly issued permits for the hunting season later that year.

And in August 2015, after the Supreme Court ordered a blanket ban on hunting Houbara bustards, officials issued "partridge hunting" licences to Arab royals instead. But locals say that is not what they killed on the ground.

Several eyewitnesses told the BBC of bustard-hunting sessions that took place after the ban, in the remote desert town of Nurpur Thal and the village of Mahni, Bhakkar district.