LGBT groups have expressed their outrage after a transgender prisoner in Brazil was allegedly "pulverised" by police and prison guards.

According to reports, Veronica Bolina was stripped naked and her head shaved in the brutal assault.

Graphic images have emerged showing her lying partially naked on the ground in front of a group of officers and other prisoners in Sao Paulo.

The pictures, which show Bolina with a badly swollen face were leaked online, sparking outrage across Brazil.

It was reported that Bolina was set upon by officers on three different occasions after being taken into custody. However, officials have denied that she is being victimised.

An official police statement claims she was attacked by prisoners when she was seen performing a sex act on herself in her cell and that officers were forced to intervene. It has been claimed that her injuries were the result of a struggle after she bit an officer on the ear.

LGBT campaign groups have condemned the attack. One campaigner Susane Montalvo Sarabia, said: "It is just sickening that in this day and age such things as this still happen. They have pulverised that poor woman's face and are now trying to cover it up. Whether she is innocent, guilty, transgender or straight doesn't matter. The police should not be allowed to do this to anyone."

The 25-year-old had previously been arrested over an alleged attack on her 73-year-old neighbour, it has been reported.

A spokesman for the prosecutors office said she had been moved to a detention centre where she has an individual cell until the court case.

Authorities in Sao Paulo are now investigating the matter.