A New Jersey court has ruled against the son of Belva Plain in a dispute over the late author's estate.

John Plain had claimed his mother, the bestselling author of more than 20 novels, and sisters had schemed to cut him out of her will.

Attorneys for Belva Plain's estate argued that her son had signed an agreement in the 1990s vowing not to contest her will.

Friday's decision in state Superior Court in Essex County dismissed John Plain's claim. Plain's lawyer said he was reviewing the decision.

Belva Plain began writing her novels after raising her children and becoming a grandmother. When she died in her sleep last fall at her home in New Jersey at age 95, more than 28 million copies of her books were in print.