San Juan, Puerto Rico ? An investigation into three apparent suicides at the Guantanamo Bay prison has found that other detainees may have helped the men hang themselves or were planning to kill themselves too.

Authorities who searched other cells after the three were found hanged discovered instructions on tying knots, along with notes in Arabic that were “relevant” to an investigation of a possible broader plot, officials said in court papers filed late Friday in Washington.

The detention center’s commander, Navy Rear Adm. Harry B. Harris, said in an affidavit that investigators believe “the suicides may have been part of a larger plan or pact for more suicides that day or in the immediate future.”

Authorities confiscated personal papers from nearly all 450 prisoners at Guantanamo Bay to “determine whether other suicides were planned or likely to be planned,” Carol Kisthardt, the Naval Criminal Investigative Service agent in charge of the investigation, said in an affidavit.

Both affidavits were filed in support of a request for a judge to appoint a special review panel to review all the detainees’ documents, which include letters from attorneys.

Attorneys for Guantanamo detainees have condemned the confiscation of the legal papers as a violation of attorney-client privilege and asked a judge to order their immediate return.

Investigators said they confiscated about 1,100 pounds of personal documents after three detainees were found hanging from their steel mesh cells before dawn on June 10 – the first reported deaths of prisoners at the prison.