Bradley Manning woman wig
US soldier Bradley Manning sent a Captain a photo of himself dressed as a woman (Reuters)

WikiLeaks whisteblower Chelsea Manning may be transferred to a civilian prison so she can receive treatment for her gender disorder, according to defence officials.

Manning, formerly known as Bradley, was jailed in August for stealing classified military documents and sending them to the anti-secrecy website WikiLeaks.

The former private has requested hormone therapy to continue her development into a woman, the first ever request by a transgender military detainee.

US defence secretary Chuck Hagel has approved a military plan to find a way of transferring Manning to provide the treatment without breaking military policy.

"No decision to transfer Private Manning to a civilian detention facility has been made, and any such decision will properly balance the soldier's medical needs with our obligation to ensure she remains behind bars," said Pentagon press secretary Rear Admiral John Kirby.

Despite not being able to leave the service because of her 35-year prison sentence, transgender people such as Manning cannot serve in the US military and the US Department of Defence does not offer any treatment for transgenders.

Manning Wikileaks
US soldier Bradley Manning apologised for hurting his country by leaking classified documents (Reuters)

Officials told the Guardian that keeping Manning in a military prison without access to the treatment she needed could be viewed as cruel punishment.

Manning has been diagnosed multiple times with gender dysphoria, the feeling of being a woman in a man's body. The military did not oppose Manning's desire to live as a woman nor to change her name from Bradley to Chelsea.

Hagel said that the prevention of transgender people from serving in the US armed forces "continually should be reviewed" and that "every qualified American who wants to serve our country should have an opportunity if they fit the qualifications and can do it."

The former intelligence analyst was jailed for handing more than 700,000 confidential US military and government documents to Wikileaks for publication after working in Iraq in 2009 and 2010.