Chelsea Manning says she tried to kill herself last month while in solitary confinement as punishment for an earlier suicide attempt.
The jailed transgender US soldier says the incident occurred on 4 October on the first day of her isolation, according to The New York Times.
Manning was sentenced to 14 days in solitary confinement for attempting suicide in July.
Seven of those 14 days were to have been suspended provided Manning didn’t get in ‘trouble’ in the subsequent six months.
After this latest attempt, Manning remained held in solitary but was placed on suicide watch and transferred to a special observation unit.
In addition to confirming the suicide attempt, Manning dictated over the phone to a member of her volunteer support network detailing an alleged bizarre sequence of events on 10 October.
Manning claims four people impersonating guards conducted an attack on the prison barracks at Fort Leavenworth, Kansas where she is being held.
The prisoner says the alleged attackers tried to get her to escape but she refused because she did not believe they were actual guards.
Manning is serving a 35-year sentence for passing data to WikiLeaks and attempted suicide in July over lack of treatment for her gender dysphoria and more recently went on a five-day hunger strike.
The US army has since agreed to provide Manning with gender transition surgery in April.