The man who masterminded the Sept. 11 terrorist attacks opposes the nomination of Gina Haspel to head the CIA.

Khalid Shaikh Mohammed is backing the Senate intelligence panel’s Democrats prior to Wednesday’s hearing on whether to confirm the longtime CIA agent to lead the organization.

According to The New York Times and other news outlets, Mohammed asked a military judge at the Guantanamo Bay prison in Cuba to share six paragraphs he had written about Ms. Haspel with the Senate panel.

Ms. Haspel oversaw a black-site prison in Thailand where two al-Qaeda terrorists, one of them under her watch, were waterboarded and subjected to other harsh interrogation techniques that opponents call torture.

It is not known whether Ms. Haspel played any personal role in Mohammed’s interrogation. After his 2003 capture in Pakistan, he was held and interrogated at secret CIA facilities in Afghanistan and Poland.

Marine Lt. Col. Derek A. Poteet, Mohammed’s lawyer in his military tribunal, described his client’s request to the Times.

He said he had submitted the request to Army Col. James Pohl, who is overseeing pre-trial procedures in the tribunal, which could condemn Mohammed to death. It was not immediately clear whether Col. Pohl would approve the request.

According to Col. Poteet, Muhammad submitted an article titled “Additional Facts, Law and Argument in Support,” containing “six specific paragraphs of information” from the Al-Qaeda leader who plotted the deaths of 3,000 Americans in the 2001 attacks.

“I am not able to describe the information,” Col. Poteet said, telling the Times that the information was from Mohammed himself, not from the government papers about the treatment of terrorism suspects.