Killer Joran van der Sloot badly beaten up in Peruvian prison

Killer Joran van der Sloot has been beaten up in prison, his lawyer has said.

Van der Sloot, 35, is convicted for the killing of Stephany Flores Ramírez in Peru back in 2010, while he is also the prime suspect in the disappearance of Natalee Holloway in 2005.

The mystery of Holloway's disappearance remains one of the US's most chilling missing person cases after the cheerleader never showed up for her flight back home to Alabama from Aruba.

She was just 18 at the time of her disappearance and with her body never found, she was declared legally dead some seven years later in 2012.

A federal affidavit cited by Fox News read: "Van der Sloot went on to admit that he had been with Natalee on the night of May 29/30, 2005, and that he had thrown her to the ground after she had attempted to stop him from leaving her."

Facebook/Natalee Ann Holloway

While van der Sloot was initially arrested - given he was one of the last people seen with Holloway - he was subsequently released over a lack of evidence.

Van der Sloot is currently serving a 28-year sentence for the murder of Ramírez in Peru, and is waiting extradition to the US on extortion and wire fraud charges.

It was announced earlier this month the killer would be handed back to the US, with Holloway's family confirming it in a statement.

Holloway's mother, Beth, shared the news, saying: "Almost exactly eighteen years later, her perpetrator, Joran Van der Sloot, has been extradited to Birmingham to answer for his crimes."

The Peruvian government has since allowed American authorities to take in the Dutch citizen 'for his prosecution in the United States for the alleged commission of the crimes of extortion and fraud, to the grievance of Elizabeth Ann Holloway', as per Peru Minister of Justice and Human Rights Daniel Maurate Romero.

UPI / Alamy Stock Photo

There had been speculation that the killer's beating in Peruvian prison may be due to his upcoming extradition to the US.

But speaking to ABC News, van der Sloot's attorney, Maximo Altez, said he doesn't believe the beating has anything to do with it.

He did add that it may be connected to gang rules inside of the Challapalca Prison, where van der Sloot is being held.

While Altez did not disclose the injuries the killer has suffered, he did confirm his client is currently in the prison's medical aisle.

The attorney has also asked the Peruvian Justice Ministry to transfer him to another prison as soon as possible while he awaits his extradition.