Troubled pop star Britney Spears has been given visitation rights to her two sons, two months after her rights were revoked, and she has spent a few hours with them.

The lawyer for Spears's ex-husband Kevin Federline confirms that his client has agreed to a modification of a Jan. 4 court order, which gave Federline sole physical and legal custody of her sons, one-year-old Jayden James and two-year-old Sean Preston.

Elliot Mintz, a spokesman for Federline, credited Spears's father, James Spears, for the breakthrough.

"James Spears went a long way in terms of stabilizing an environment that surrounded Britney which was wildly in flux," said Mintz, who confirmed that James Spears will be present during those visits. 

Mintz confirmed Sunday that the pop star spent three hours with her sons but would not say where or when the meeting happened.

The pop singer had not been allowed to see her sons since an incident at her home that led to the first of her two hospitalizations in a psychiatric facility this year.

Both incidents were at the tail end of a year-long spiral downwards in which Spears briefly went to rehab, shaved her head, partied at all hours and exhibited bizarre behaviour.

After the second hospitalization on Jan. 31, her parents rushed to Los Angeles to take care of her affairs. 

Earlier this month, a California court granted conservatorship to her father, giving him control over the 26-year-old's business and legal affairs.

Her parents have since urged to have her visitation rights restored in the hopes it might help their daughter heal.

Ex-manager ordered to keep distance

On Thursday, a Los Angeles judge ordered the singer's former manager to stay away from her.

Sam Lutfi must not come within 228 metres of the singer until March 17.

In papers requesting the order, Britney Spears's mother, Lynne Spears, claimed Lutfi had drugged the star, cut her home phone and yelled at her.

Meanwhile, Spears hired a lawyer to challenge her father's conservatorship.

Lawyer Jon Eardley filed documents last week in a Los Angeles court on behalf of his client, claiming that James Spears has denied his daughter "fundamental rights to associate freely and to utilize telephones and other methods of communication with the outside world," and also taking away "significant liberties."

Eardley says he was hired by Spears on Feb. 12.

"The last time she attempted to call me, the telephone was taken away from her, and the number was disconnected the next day," Eardley said in a written declaration.

With files from the Associated Press