The Massachusetts attorney general on Monday joined in to halt the sale of multimillions in artwork that the Berkshire Museum planned to send to the auction block next month.

A 26-page filing from Attorney General Maura Healey sides with motions from two other groups, one of which includes three sons of artist Norman Rockwell, in a legal attempt to stop the museum's sale of art at Sotheby's on Nov. 13.

Two works by Rockwell are estimated to bring about $40 million and several more pieces could boost that total.

The case will be heard at 11 a.m. Wednesday by Judge John Agostini. 

"Any sale of the art in question in violation of the law would result in irreparable harm to the public interest," according to the response filed by Healey's office.