Shania Twain pens a tale of betrayal

Music star Shania Twain has revealed how she put her "heart, soul and dreams" into her New Zealand home near Wanaka - while her husband was having an affair with her friend, his secretary.

The Canadian country singer has written a tell-all memoir about the end of her 14-year marriage to producer Robert (known as Mutt) Lange after his affair with her close friend Marie-Anne Thiebaud.

Twain (45) ended up marrying Thiebaud's former husband, Frederic.

In the book From this Moment On she writes about Motatapu, the couple's high-country sheep station near Wanaka.

"I started designing a homestead for us shortly after we bought it and began putting my heart, soul and dreams into the plans," she said.

"I dreamed of riding horses across the vast plains, along winding riverbanks and through golden tussocks in the sharp, beaming sunshine of the land of the Kiwi."

The pair bought the 24,731ha Motatapu Station and Mt Soho for $21.5 million in 2004.

She talked fondly of her family-time in New Zealand: "Every year Mutt, Eja and I would go there for several months, living in a small caravan parked in one of the sheep paddocks ... we enjoyed camping out while our home was being built."

She returned from her home in Switzerland in early 2008 to finish the project.

While in New Zealand then she became suspicious: "Our New Zealand trips were usually spent in three- to four-month stretches. During this stretch in New Zealand, Mutt returned to Switzerland twice, while Eja and I stayed behind."

Back in Switzerland, in March 2008, Twain discovered the affair: "The same friend who'd 'comforted' me over the phone, expressing how absurd it was of me to have any such suspicions of my husband. The idea that she was the mistress... had not even entered my mind."

In January, she married Mr Thiebaud, "the only person who understood" [the situation].

Twain no longer owns Motatapu.