Two cousins whose feud over their family supermarket chain prompted an employee walkout and customer boycott are battling again in court.

Arthur S. Demoulas sold his stake in the Market Basket chain in 2014 after a massive protest by workers who were upset that a board controlled by him he fired his cousin, Arthur T. Demoulas. The chain's customers supported the workers and began shopping elsewhere. Arthur T. Demoulas got his job back, and the chain has turned around.

Last week, Arthur S. Demoulas and his sister-in-law filed a lawsuit alleging they have been excluded from involvement in an IRS audit of the 76-store chain.

A spokeswoman for Demoulas Super Markets told The Boston Globe that the company had always planned to include Arthur S. Demoulas in the audit process.