Bilal Mansoor Khawaja beams as he runs his palms over the ivory coat of a white lion, one of thousands of exotic animals at his personal "zoo" in Karachi, where a thriving wildlife trade caters to Pakistan's gilded elite.

"These are... (some) of the rarest animals I own," boasts the 29-year-old industrialist of his leashed lion.

Pakistani laws make it easy to import exotic animals, but once inside the country regulation is almost non-existent.

This has led to an untold number of such creatures - especially big cats, seen as symbols of wealth and power - being imported or bred across Pakistan in recent years, much to the horror of helpless wildlife officials.

Khawaja estimates there are up to 300 lions within Karachi's city limits alone, kept in gardens, inside rooftop cages, and at farm houses across the sun-baked metropolis of about 20 million - notorious for its grinding traffic, crumbling infrastructure, and lack of greenspaces.

Khawaja calls his handful of lions and a tiger the "crown jewels" of a larger collection of more than 4,000 animals he has amassed in recent years.

He insists his collection - made up of some 800 different species - is not about status or prestige but simply a manifestation of his love for pets.