Rimes, whose affair with "CSI: Miami" actor Eddie Cibrian while both were married to others caused a scandal three years ago, checked into an unidentified treatment center on Wednesday - the day after her 30th birthday.

"LeAnn has voluntarily entered a 30-day in-patient treatment facility to cope with anxiety and stress," her publicist Marcel Pariseau said in a statement to People magazine. "While there will be speculation regarding her treatment, she is simply there to learn and develop coping mechanisms."

Pariseau told the celebrity magazine that the "How Do I Live" singer was not seeking help for substance abuse or an eating disorder, despite recent photos that have sparked debate over her thin figure.

Rimes denied earlier this year that she had anorexia.

The Grammy-winning singer, who became a country music star at age 13, told People that her stay was "just a time for me to emotionally check out for a second and take care of myself and come back in 30 days as the best 30-year-old woman I can be."

Cibrian, who married Rimes in April 2011 after they both divorced, said his wife had his full support.

Rimes will exit her program to perform some scheduled concerts in September, Pariseau said.

(Reporting By Jill Serjeant; Editing by Bob Tourtellotte, Bernard Orr)

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