Gwen Stefani has formally filed for divorce from her husband of 13 years, Gavin Rossdale.

According to Radar Online, the "Hollaback Girl" singer cited irreconcilable differences in officially filing documents in Los Angeles on Aug. 3. The petition did not cite a date of separation for the parents of their three young children.

The website adds Stefani is seeking joint legal and physical custody of the children and has asked that she not be required to pay spousal support. Reports are the couple did not have a prenuptial agreement in place and have a net worth of an estimated $135 million, well over half of which was earned by Stefani.

Not long ago, Stefani teared up while discussing the status of what was thought to be her blissful union with Rossdale.

"If I look back on the whole thing, the one thing that's been constant is that we both want the same thing," Radar reports she said during a "Today" show interview last January. "We both want to be married. We both want to be good parents, and so I feel really proud of what we've done together."

Later during that same month, Rossdale saluted his wife as "such a great person" that she had taught him how to be better.

Radar now reports Stefani may fear her husband cheated on her with their nanny.

"Gwen is absolutely devastated about the marriage ending, and she has been inconsolable," a source told Radar. "But she had no other choice. She was very suspicious that Gavin was involved with the nanny."

Reports are Rossdale has denied any wrongdoing.

"Gavin was the love of Gwen's life and she gave it everything she could and really did everything possible to save the marriage," the source added. "Gavin just didn't seem to be putting as much into it as she did."