Shania Twain split from husband because he was having an affair

Shania Twain's split from husband Robert "Mutt" Lange, after 14 years of marriage, was due to his relationship with another woman, it has been claimed.

After the separation was announced last week, Lange, a music producer, called the split "an unfortunate thing," adding, "it's literally just a growing apart, that's all."

But sources close to the couple claim that there was another woman involved: Marie Ann Thiébaud, a longtime secretary and manager of the couple’s chateau in Switzerland.

A source tells People.com, "Mutt and Marie Ann left their spouses for each other and are still in a relationship."

But Lange denies the the claims, insisting that, "it's absolutely not the reason [for the separation]," and he has also blasted talk of him being in a romantic relationship with Thiébaud: "I'm not, no," he said. "It's not true."

Lange, who has produced albums for artists such as Def Leppard, AC/DC and Foreigner, heard Shania's 1993 single God Ain't Gonna Getcha for That. He called to tell her that he admired the song. One thing led to another, and they married on December 28 -- in the same year..

The couple began writing songs together. Whose Bed Have Your Boots Been Under? -- their first collaboration -- was a hit.

The couple have a son, Eja D'Angelo, who was born on August 12 2001.

Twain, 42, is said to be "devastated. This came out of left field. . . She loved him," said a source.