The landlady of a British pub has designated her establishment a "smoking research centre" in an attempt to circumvent a smoking ban that has seen business nosedive.

Customers at the Cutting Edge pub in South Yorkshire, England, fill out a questionnaire about their smoking habits to satisfy legal requirements before heading into a separate room to light up.

England and Wales banned smoking in enclosed public places two years ago. Pubs across the region saw steep drops in beer sales, forcing more than 2,000 establishments to close in the last year, according to the British Beer And Pub Association.

Landlady Kerry Fenton told The Mail newspaper she decided to give the smoking room a try after a customer discovered a loophole in the law. She turned an existing tap room, which is separate from the rest of the pub, into the smoking room.

In the five days since she made the change, customer numbers have quadrupled, she said.

"It's given business a shot in the arm and it's all in the name of research, legal and above board," she told the Sun newspaper earlier this week. "I'm a non-smoker but I believe in the freedom of the individual."

The local council says it intends to enforce the smoking ban at the pub.