A female MMA fighter punched an alleged pervert she claims was performing a sex act while she was taking part in a swimwear photo shoot.

Joyce Vieira and a friend were taking pictures on the Praia do Braga beach in the town of Cabo Frio in the Brazilian state of Rio de Janeiro when she said she saw a man masturbating.

The 27-year-old claims the man had his shorts down and was standing in front of her and her friend while performing a sex act on himself.

In images of her attack on the unsuspecting man, named by Brazilian media as Josenei Viana Ferreira, she can be seen launching at the shirtless suspect.

Dressing in a black swimsuit the martial artist took action by raining down a series of punches on the 26-year-old man, who was topless but dressed in swimming shorts.

Marial arts fighter Joyce Vieira punched the man she claims was performing a sex act in front of her as she took part in a photo shoot on a beach in Rio de Janeiro

Joyce Vieira is known as an MMA fighter in her home country of Brazil and has posted pictures of her MMA training regimes

The MMA fighter claims the man was standing with his shorts down as he masturbated during her swimwear shoot

She said: 'When I looked over there he had his shorts down and was standing on a path where people pass all the time, including children. He was visibly erect, making sounds and moaning.'

In the photos, the martial artist, dressed in a black swimsuit, can be seen punching Ferreira,

Vieira reported the case with police and Ferreira was later arrested for committing an 'obscene act' but has since been released after giving a statement and denying the crime.

After his release, Vieira told local media: 'We feel powerless. It's very strange because he's going to be in the same city as me, and who knows he might be in the same places.

'That's why I have received an innumerable number of messages from women saying that [in similar situations] they didn't file a report, because they know the suspects would end up being released. I think the punishment for these cases should be more severe.'

Vieira told police she approached the suspect but he would not speak to her so she began punching him

The MMA fighter training before she attacked a man she claims was pleasuring himself in front of her as she took part in a photo shoot

Vieira said she has received many messages from women who have not reported similar incidents to the police

Vieira says she had tried to speak to the man but he refused to speak to her so she reacted.

The Civil Police told reporters the suspect had claimed he 'was urinating' on the beach before Vieira approached him.

The Inspector Specialised in Attending to Women in Cabo Frio, Juliana Rattes, said the case will be taken to the Public Ministry 'who will act together with Special Criminal Court'.

MMA fighter Vieira, 27, who is a specialist in Muay Thai and Jiu-Jitsu, often posts videos of her intense training sessions online.

The case is ongoing, according to Brazilian media.