Prague - Czech-born architect Jan Kaplicky, creator of organic-shaped buildings and a design visionary, died suddenly at the age of 71, medical services confirmed Thursday.

Kaplicky collapsed on a Prague street on Wednesday evening. He died of heart failure despite efforts to resuscitate him just hours after his daughter was born, his relatives said.

"His heart betrayed him at a moment when he wanted to celebrate this joyful event," the family said in a statement provided to the Czech news agency CTK.

Kaplicky designed buildings such as Selfridges department store in Birmingham and the Lord's Cricket Ground media centre in London.

"I am shocked and devastated. Jan was a great architect, valued colleague and good friend," acclaimed British architect Norman Foster said in a statement.

Kaplicky emigrated from the then communist Czechoslovakia in 1968 and set himself up in Britain.

He worked with big-name architects, including Foster, Richard Rogers and Renzo Piano, before establishing his own studio, Future Systems.

His professional comeback to his native Prague went awry.

His winning design for Prague's new National Library, dubbed a blob after its octopus-like shape, sparked a controversy.

While former Czech president Vaclav Havel praised the building, the country's current head of state, Vaclav Klaus, slammed the design and the city blocked its construction.

"He was not conventional," his friend, country music singer Pavel Bobek, told Czech Television. "Kaplicky insisted that a man is not rectangular."

Kaplicky is outlived by his second wife Eliska Kaplicky Fuchsova, their newborn daughter Johana and son Josef from his first marriage with British architect Amanda Levete. (dpa)