A recent audit of California's prison system has revealed that almost one third of 144 female prisoners who were sterilised between 2005 and 2013 were operated on without consent.

The report, released by the Californian State Auditor on Thursday, found that 39 female prisoners had been surgically sterilised illegally, without the consent of the women involved.

Californian state law states that sterilisation procedures can only take place between 30 and 180 days from the time a woman agrees to the procedure, “to provide the patient with enough time to reflect on her choice and to make sure she desires sterilization.”

READ: PAEDOPHILE NURSERY WORKER, 28, ASKS TO BE CHEMICALLY CASTRATED

There are other rules in place to protect female prisoners during this procedure: the patient must be 18, she must be allowed a witness of her own choosing, she must receive counselling, and she must understand her ability to revoke her consent.

Once the patient signs the consent form, it must also be signed by the person who obtained the consent as well as by the operating physician. By signing the form, the physician attests that he or she has explained the permanence of sterilisation and believes the patient is mentally competent.

READ: SHOULD PREGNANT DRUG ADDICTS BE CHARGED WITH ASSAULT AGAINST THEIR UNBORN BABY?

However, as proven by this recent audit, it was found that nearly 40 women were operated on illegally - without the rules being followed.**

**

In some cases, the inmate's doctor did not sign the form to indicate that the patient was mentally competent, understood the long-lasting impact of the procedure.

Other cases saw doctors falsifying documents by saying the proper waiting period had been adhered to, when in fact it had not.

Senator Ted Lieu said that the recent sterilisation findings had made "his stomach sick".

"The audit shows systemic failures by the federal receiver in the sterilisation of female prisoners.

"I'm also surprised that the receiver makes the argument that they had no legal duty to make sure the prison employees comply with the consent procedures. That is a ludicrous argument."

READ: SAMANTHA BRICK SAYS 'WOMEN LIKE BABY P'S MUM SHOULD BE STERILISED'

The investigation by the state audit was requested after an investigation by the Centre for Investigative Reporting last July, revealed that 132 women had received tubal ligations in violation of prison rules from 2006 to 2010.

In addition to this, it was expected that over 100 more inmates had received similar illegal treatments in the 1990s.

Most of the sterilised inmates are women of colour, and read below a High School level. Many of the operations were allegedly performed by Dr James Heinrich, who has previously stated that sterilisations are worth the money "compared to what you save in welfare paying for those unwanted children."

You may also like: Should female criminals be sterilised?