Several former employees, who insisted on anonymity, confirmed that they were eager to talk with the shareholder group and said they might have valuable information.

“I would say more, but I don’t want somebody knocking on my door and asking for $50,000 back,” said one former employee who worked on Freddie Mac’s internal financial controls. “It’s almost like bribery; I felt that I was supposed to sign the agreement, take the money and keep all their secrets.”

The severance deals were so strict, according to former employees, that they prohibited those who accepted them from saying almost anything about their old jobs or even about the secrecy pledges themselves.

“I was told that in volunteering to take a buyout, I couldn’t even talk about the agreement or it would be off the table,” said an 18-year veteran of Freddie Mac, who insisted on anonymity because of the restrictions. “I was told that you don’t talk about the terms of agreement, you don’t talk to the news media and you don’t talk to attorneys involved in lawsuits against the company.”

Lawyers for pension funds that have filed a class-action lawsuit against the company say the secrecy provisions have already muzzled at least two dozen former employees with potentially important information.

Spokesmen for both Freddie Mac and the Federal Housing Finance Agency said they could not comment on the case because it is in litigation.

In a legal brief filed in August, the Federal Housing Finance Agency refused to confirm that the secrecy pacts even existed, saying their existence was “hypothetical.” But if the restrictions did exist, the agency continued, neither shareholders nor the courts had any authority to interfere with them.