The company’s board, including Allison, has supported the family’s decision not to sell.

SPG is thus accusing the family and the board of “unilaterally” blocking shareholders from realizing its offer.

“[We] believe that the company’s common shareholders, and not the Taubman family, should decide the future of the company and that the company board should not prevent the company’s common shareholders from receiving $20.00 per share in cash for their shares in the offer,” SPG wrote in its letter.

SPG has been attempting to gain control of TCI since November, when they made their first public offer of $17.50 a share. The company increased its offer to $18 in December.

In January, SPG partnered with Westfield America, Inc., to make a tender offer of $20 a share. Each time, according to the TCI brief, SPG claimed to be making an offer equivalent to the “full value” of the shares.

Shares of TCI, which closed Friday at $17.27, traded at $13.32 at the time of the $18 tender offer, according to SPG spokesperson Burns. He said TCI shares had not closed above $16.01 in its ten-year history prior to the tender offers—evidence that the offers had raised TCI share value.

The SPG brief had been sealed until the court granted a motion to release it last Thursday. The motion was filed by The Detroit Free Press, The New York Times and Dow Jones & Co., the parent company of The Wall Street Journal.

This is not the Taubman family’s first run-in with the law. A. Alfred Taubman is currently serving out a sentence for price fixing while he directed the Sotheby’s auction house.

—Staff writer Stephen M. Marks can be reached at marks@fas.harvard.edu.