Prince Albert of Monaco and Charlene Wittstock have exchanged wedding rings and vows in church - amid persistent rumours that the ex-Olympic swimming star was almost a runaway bride.

The 53-year-old prince and his South African bride took part in the Roman Catholic ceremony at Monaco Cathedral this afternoon.

The bride entered the cathedral in a white dress with veil, accompanied by her father, and with a 15-foot train behind her.

Her husband, who was wearing a white military uniform, winked at her at the altar.

The pair also tied the knot in a Monte Carlo civil ceremony on Friday.

But the excitement of the two events was marred by reports that Miss Wittstock had second thoughts about becoming Her Serene Highness and fled to Nice airport with a one-way ticket home.

It was suggested she had found out a secret about Albert, who has two children with other women but is yet to produce a legitimate heir.

Miss Wittstock, 33, was apparently intercepted by royal aides and persuaded to stay, before Monaco's royal palace dismissed the claims.

"These rumours have no other goal than to severely damage the reputation of the monarch and thereby that of Miss Wittstock and severely undermine this happy event," a statement said.

The bride's father added that she did leave Monaco earlier this week - but only to head to Paris for some pre-wedding shopping with her mother.

The wedding was attended by the great and the good of Monaco and royal relatives and friends from all over the world, including the Earl and Countess of Wessex.

James Bond actor Sir Roger Moore, France's richest man Bernard Arnault and fashion designers including Karl Lagerfeld, Roberto Cavalli and Giorgio Armani were also on the guest list.

Composer Jean Michel Jarre took a starring role in a concert after the civil ceremony and an extravagant fireworks display lit up the sky of the Cote D'Azur to add to the glamour of the occasion.

After this afternoon's religious wedding comes a dinner prepared by Michelin starred chef Alain Ducasse and a grand ball.

The couple initially met in 2001 while Miss Wittstock was at a swimming competition in Monaco but she was not interested in romance, preferring to concentrate on her sport.

Even so she was quoted as saying a year ago that she knew at the time that he was "the one".

The pair kept in touch and, in 2008, the South African moved to Monaco, although the prince did not propose for another two years.

Prince Albert II became head of the Grimaldi family, who have ruled the tiny principality for more than 800 years, after his father, Prince Rainier III, died in 2005.

His mother, the former film star Grace Kelly, died in a car crash in 1982.

Prince Albert and his bride, who is 20 years younger than him, are expected to be planning a family sooner rather than later.

The law was changed in 2002 to allow his sisters - Princesses Caroline and Stephanie - or their children to inherit the throne, to stop Monaco returning as a protectorate to France.