Formula One joins family, friends and fans at funeral service for motor racing legend Niki Lauda

Formula One's most famous names joined family, friends and fans of motor racing legend Niki Lauda, as the sporting world gathered in Vienna for the F1 driver's funeral.

The wooden coffin of the three-time champion lay in St Stephen's Cathedral and was decorated with his red racing helmet by his widow, Birgit and surrounded by six white candles and rose wreaths, with two large portraits of Lauda behind.

The Austrian died on May 20 at the age of 70, less than a year after undergoing a lung transplant.

The helmet of the former Formula One driver Niki Lauda, is placed on top of his coffin. Credit: AP

Formula One driver Lewis Hamilton joined the service in Vienna, dressed in black, sunglasses and a trilby hat.

He bowed his hat as Lauda's coffin was brought out of the cathedral, followed by mourners.

F1 World Champion Lewis Hamilton joined the funeral service in Vienna. Credit: AP

Toni Faber, the cathedral's priest who gave the sermon for Lauda, said: "He was an unpretentious, humble, shining star among the racing drivers

"He had a sense of humour, was true-to-life, target-oriented and no-nonsense."

Before the service began, hundreds of fans walked by the coffin, many of them crossing themselves and taking mobile phone photos.

Mourners paid their respects to the three-time world champion. Credit: PA

Lauda, who won two of his Formula One titles after a horrific crash in which he suffered serious burns, later became a prominent figure in the aviation industry and in recent years served as a non-executive chairman of the Mercedes F1 team.

Lauda won the F1 title in 1975 and 1977 with Ferrari and again in 1984 with McLaren.

Former F1 World Champion Alain Prost, front left, walks next to the coffin as it is brought out of St Stephen's. Credit: AP

In 1976, he was badly burned when he crashed during the German Grand Prix, but he made an astonishingly fast return to racing only six weeks later.

Lauda remained closely involved with the F1 circuit after retiring as a driver in 1985.

Birgit Lauda stands next to her husband's coffin, alongside two large pictures of Lauda wearing his distinctive red baseball cap. Credit: AP

Several Formula One stars were expected to attend the service along with Austrian President Alexander Van der Bellen and actor Arnold Schwarzenegger.

F1 champion Lewis Hamilton points to his Niki Lauda tribute after winning the Monaco Grand Prix. Credit: AP

Formula One paid its own tribute to Lauda at the Monaco Grand Prix at the weekend, holding a minute's silence as drivers and teams donned red caps so familiar with the former champion.

Hamilton wore a red baseball cap - mirroring the ones wore by Lauda - with the name of the sporting legend emblazoned on the front.