BOSTON (AP) — Norman Rockwell's three sons were among several people who went to court on Friday seeking to halt a museum's plans to sell 40 works of art, including two by him.

A complaint seeking a temporary restraining order filed in Berkshire Superior Court alleges the board of trustees at the Berkshire Museum in Pittsfield contracted with Sotheby's for a public auction of the works before it announced its plans publicly, acted in breach of its fiduciary duties and trust and acted without legal authority to sell the art.

The planned sale is against Massachusetts laws establishing the museum, which requires the museum to maintain any gifts it receives "for the people of Berkshire County and the general public," the complaint says.

"Once sold, it is highly unlikely that any of the pieces will remain in Berkshire County or in a public institution where they can be seen and enjoyed," the complaint says.

Besides Thomas, Jarvis and Peter Rockwell, the plaintiffs include two local artists and several members of the museum. They are represented by the Boston law firm Foley Hoag LLP.

The museum has consistently stood by its decision to sell the art.

"We believe we have strong legal grounds for our deaccessioning and we are confident in our new vision plan which will allow this important local museum to continue to contribute to the educational and cultural life of this region for another century," trustees president Elizabeth McGraw said in a statement on Friday.

The museum came under intense national and local criticism after it announced in July that is was auctioning the art.

The American Alliance of Museums and the Association of Art Museum Directors said in a joint statement that the sale violated a sacred museum rule that collections are not to be sold to pay bills.

The works for sale include Rockwell's "Shaftsbury Blacksmith Shop" and "Shuffleton's Barbershop," both of which the illustrator gave as gifts to the museum when he lived in nearby Stockbridge. Works by Alexander Calder, Albert Bierstadt and George Henry Durrie also are on the auction block.

Museum trustees and officials say the museum is in dire financial straits and may close for good if it doesn't sell the works. They say it is hoped that the sale will raise as much as $60 million, which will be used to boost the endowment by $40 million, with the other $20 million being used to renovate the museum as it changes its mission to focus more on natural history and science.

The complaint says the museum's financial troubles are greatly exaggerated.