(Reuters) - Cher has sued former Republican U.S. Representative Mary Bono, widow of her late musical partner and ex-husband Sonny Bono, and his estate in Los Angeles federal court for allegedly withholding her share of royalties in Sonny & Cher songs.

Cher asked the court on Wednesday to block the trust that administers Sonny Bono's royalties from terminating her rights from a divorce settlement that granted her half of Sonny & Cher's royalties.

Mary Bono, the trust's sole trustee, didn't immediately respond to a request for comment; neither did Cher's attorney Peter Anderson of Davis Wright Tremaine.

Cher and Sonny Bono began performing together as Sonny & Cher in 1964, married in 1967, and divorced in 1978. The complaint said they had agreed to divide the royalties from songs like "I Got You Babe" and "The Beat Goes On" equally after their divorce.

Under the Copyright Act, authors can cancel transfers of their copyrights and reclaim them after 35 years in some circumstances. The provision has been at the center of recent disputes involving Marvel, its parent company Disney, and Major League Baseball's Philadelphia Phillies.

According to the complaint, the Bono Collection Trust claimed that its 2016 notices of termination to several music publishers also ended Cher's royalty rights.

Cher said the trust told her last month that it would stop paying her share of the royalties when the terminations go into effect, and that she no longer had the right to approve uses of their songs, among other things.

Cher asked the court for a declaratory judgment that the estate didn't terminate her rights, and requested at least $1 million in damages for breaching the divorce settlement.

The case is Cher v. Bono, U.S. District Court for the Central District of California, No. 2:21-cv-08157.

For Cher: Peter Anderson of Davis Wright Tremaine