Manning has since been released, but is being 'monitored' by officials

The ex-US-soldier tried to hang herself inside a cell at Fort Leavenworth prison in Kansas and was

Chelsea Manning, the ex-US-soldier who is serving a 35-year prison sentence for leaking thousands of secret military documents, attempted suicide in prison.

The imprisoned transgender 28-year-old was hospitalized briefly, a US defense official said Wednesday after reports said she attempted suicide at Fort Leavenworth in Kansas.

'She was taken to a local hospital in the Fort Leavenworth area yesterday morning, and she was returned to the disciplinary barracks yesterday morning,' the official told AFP, speaking on condition of anonymity.

The official had no information on Manning's medical condition.

A source told TMZ that Manning tried to hang herself inside a cell at the all-male prison, which she has been confined to despite requesting to be moved to a female prison.

The source added that Manning is now being 'monitored.'

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Chelsea Manning (above), the ex-US-soldier who is serving a 35-year prison sentence for leaking thousands of secret military documents, allegedly attempted suicide in prison

Manning - pictured here after being found guilty, and before beginning the transition into a woman- tried to hang herself at Fort Leavenworth in Kansas on early Tuesday, a source told TMZ

Nancy Hollander, one of Manning's lawyers, released a statement Wednesday saying she had a planned scheduled call with her client for Tuesday, but it never happened.

'I had a privileged call scheduled with Chelsea at 2pm Leavenworth time yesterday, after the Army has now said she was hospitalized, but the Army gave the excuse - which I now believe to be an outright lie - that the call could not be connected although my team was waiting by the phone,' the statement reads.

'We're shocked and outraged that an official at Leavenworth contacted the press with private confidential medical information about Chelsea Manning yet no one at the Army has given a shred of information to her legal team.

'Despite the fact that they have reached out to the media, and that any other prison will connect an emergency call, the Army has told her lawyers that the earliest time that they will accommodate a call between her lawyers and Chelsea is Friday morning.

'We call on the Army to immediately connect Chelsea Manning to her lawyers and friends who care deeply about her well-being and are profoundly distressed by the complete lack of official communication about Chelsea's current situation.'

In 2010, Manning, who was then known as Bradley, leaked classified Army documents to the website WikiLeaks and was convicted on 21 counts of espionage.

She was working as an intelligence analyst in Iraq when she leaked airstrike videos, US diplomatic cables and 482,832 Army reports that went on to become known as the Iraqi War Logs and Afghan War Diary.

In 2013, Manning was sentenced on the charges to 35 years in prison.

She was born Bradley Manning, and in a statement after being sentenced she said she had felt female since childhood and wanted to be known as Chelsea,

She transitioned from male to female in prison and has requested to be moved to an all-female prison.

In May, her lawyers filed an appeal citing that she acted in the interests of the public.

In their argument, they claim she doesn't deserve the 'harsh' sentence in prison.

'For what PFC Manning did, the punishment is grossly unfair and unprecedented,' the appeal, filed Wednesday, said. 'No whistleblower in American history has been sentenced this harshly.'

Her lawyers hope to get the court to either reduce her sentence to ten years or dismiss the charges entirely, Manning said on her blog.

The reasons she gave for the appeal were being placed in solitary confinement before her trial - described as 'deplorable' and 'unconstitutional' by her lawyers - the use of 'vague evidence' for sentencing and a 'lack of evidence on charges of theft of information'.

She was hospitalized in the Fort Leavenworth prison hospital before being released, as she is being 'monitored.' (file photo above)

In 2010, Manning - pictured above before beginning the transition into a woman- leaked classified Army documents to the website WikiLeaks and was convicted on 21 counts of espionage.

She also cites a 'vague definition of 'exceeding authorized access'' in the Computer Fraud and Abuse Act and a 'lack of proof' that U.S. interests were harmed by the leak as additional reasons.

'Throughout trial the prosecution portrayed PFC Manning as a traitor and accused her of placing American lives in danger, but nothing could be further from the truth,' the appeal said.

It added that she released the documents because she 'believed the public had a right to know about the toll of the wars... the loss of life, and the extent to which the government sought to hide embarrassing information of its wrongdoing.'

Manning announced the appeal on her Twitter account, saying 'My fight is far from over. I am only just getting started.'

The American Civil Liberties Union (ACLU) wrote in defense of Manning, saying that her conviction was 'unconstitutional,' ABC reported.

It said the Espionage Act is 'unconstitutionally vague,' because it gives the U.S. government a tool 'to subject speakers and messages it dislikes to discriminatory prosecution'.

It also said that the act was used unconstitutionally when the judge refused to allow the court to consider whether the leaked documents might have been so valuable to public discussion that they justified the leak.

In 2013, Manning - pictured above before beginning the transition into a woman - was sentenced on the charges to 35 years in prison. Her lawyers filed an appeal in May citing that she acted in the interests of the public

Manning had originally been charged on 22 counts, but was acquitted of 'aiding the enemy,' which carried a potential death sentence.

While in prison, she joined with Amnesty International to sue the government for the right to hormone therapy and won the lawsuit.

She recently wrote an essay for The Guardian about the new US rules allowing transgender people to serve openly in the military.

'Gender presentation should reflect the person that you are,' Manning wrote.

'When you lose control of your gender presentation you lose an important aspect of your identity and existence.

'By setting so many caveats, time lines, standards, and training, the military is making this far, far, more complicated and bureaucratic than it needs to be.

'The simple reality is that we are who we say we are.'