When asked what the BBC’s most popular export is, a lot of people might be tempted to turn to controversial car show Top Gear or long-running family favourite Doctor Who.

But the answer is slightly more peculiar with international broadcasters instead flocking to buy 1990s sitcom Keeping Up Appearances.

Broadcasters from countries including Bulgaria, Nigeria and Latvia have purchased the rights to series one of the quintessentially British comedy, which has been sold 992 times in the last 50 years.

Broadcasters from countries including Bulgaria, Nigeria and Latvia have purchased the rights to series one of Keeping Up Appearances, which has been sold 992 times. Above, Patricia Routledge and Clive Swift, who star in the show

It beat natural history show The Life of Mammals, which is second having been sold 958 times.

In third place is another nature programme, Wild South America: Andes to Amazon, while fourth is Wild Africa, according to data released by BBC Worldwide.

Roy Clarke, creator of Keeping Up Appearances, said he thought the show was so popular because ‘everyone knows a Hyacinth’.

He added: ‘The Old Girl keeps on raising and ridding the dust.

‘It appears that she’s an international phenomenon. Wherever you are it seems there’s a Hyacinth next door, or just down the road or in the family.

‘Great fun for half an hour as a spectator – but permanently? I shouldn’t grumble. Bless her she’s been good to me.’It beat natural history show The Life of Mammals, which is second having been sold 958 times. Above, Sir David Attenborough, presenting the show

The data highlights the shows that have sold the most over the last four decades in relation to BBC’s Showcase.

It is based on the number of times a title has been bought rather than the number of territories.

So while modern shows – including Sherlock, Call the Midwife, Luther, Top Gear, Silent Witness and Planet Earth – have been purchased by more than 200 territories across the world, older shows, using this method, appear more popular.

The most purchased drama series is series one of Doctor Who, which has attracted 629 buyers from countries including Bahrain, Hong Kong, France and Chile.

Meanwhile, Top Gear is the most bought factual entertainment series, with series nine clocking up 282 sales in countries ranging from Albania, China, Iceland, Iran, Russia, the USA and beyond.

Paul Dempsey, president of global markets at the Corporation, added: ‘We are extremely proud of our heritage and back catalogue so it’s fun to look back into the archives and celebrate the enduring appeal of some of our classic shows.

‘At the same time, it’s clear that the priority for today’s audiences is event TV with high-production values.

‘It’s no coincidence that our current best sellers are premium dramas like Doctor Who and Sherlock, high-end entertainment shows like Strictly Come Dancing and Top Gear, and our world-renowned natural history programmes like The Hunt.’