The jewellery collection was a gift from her first opera-loving husband

The 11 pieces were sold by an unnamed heir who had held onto the collection since the soprano's death in 1977.

The most expensive lot in the auction, which took place at Sotheby's in Geneva, was an 11.7-carat diamond ring.

La Divina fetched $397,500 (�213,500), nearly five times the original estimate set by auctioneers.

"There was big interest from all over - collectors, professionals and fans of opera," said Sotheby's David Bennett.

"These jewels have never been on the market before."

Bidding was heavy for Callas' 18-carat gold evening bag, trimmed with diamonds, which fetched $45,500 (�24,430) - roughly nine times its pre-sale estimate.

"That was an amazing price," said Stefano Papi, the author of a book on the soprano's stage jewels. "The buyer must be someone who really loved this woman."

First husband

A large part of the collection were items given to Maria Callas by her first husband, Giovanni Meneghini, half a century ago.

Callas, famed for her acclaimed role as Tosca in Franco Zeffirelli's stage production of the Puccini opera, married the Italian industrialist Meneghini in 1949.

In pictures: The collection

She later left him for Greek shipping magnate Aristotle Onassis. They shared a stormy relationship until he wed Jacqueline Kennedy in 1968.

At the time of her death in 1977, Callas' multi-million dollar estate was the subject of much disagreement among her family and friends.

Now some of those who remember her are angry that her jewels are being sold off.

The film director Franco Zefferelli, for example, described the sale as a shameful exploitation of the opera singer's legacy.

But Sotheby's Geneva director Brett O'Connor said it would allow her fans to own a piece of her memory.

"We wanted everybody to have a chance to have a piece of someone who was so liked," he said.