Russell Brand is facing “hell on earth” inside HMP Wandsworth, a former prisoner at the south London jail has warned, as the disgraced comedian begins a sentence of more than a decade behind bars.

The 51-year-old was jailed for 10 years and six months at Southwark Crown Court on Monday after being convicted of one count of rape and three counts of sexual assault. He is currently being held at the sprawling Victorian prison, one of the largest in England.

Chris Atkins, a documentary filmmaker who previously served eight months at Wandsworth for tax fraud, told the BBC the initial adjustment to life inside the category B facility would be tough for the former Hollywood star.

“The first month is hands-down the worst. The mental shock is absolutely colossal,” Mr Atkins said, adding that the experience would be “10 times worse” for Brand due to the nature of his offences and the height of his public fall.

He warned that the physical shock of being locked inside a cramped cell for weeks with minimal human contact would be gruelling.

Brand was recently moved from an isolation unit onto a main wing, according to a source close to the former presenter, who claimed he was coping “remarkably well considering the circumstances”.

However, prison staff and former governors have highlighted the acute risks facing high-profile sex offenders in mainstream custody.

A Wandsworth staff member told the BBC that Brand’s arrival had sparked both curiosity and anger among prisoners on the landings over the nature of his crimes, forcing officers to remain alert to potential hostility.

Upon reception at the jail, Brand’s personal belongings, phone, and clothing will have been confiscated and replaced with a standard-issue grey tracksuit, alongside a basic reception pack containing tea, milk, cereal, and biscuits.

Because sex offenders are frequently targeted by other prisoners, they are often excluded from shared workspaces such as kitchens, laundries, and libraries – limiting both their time out of cells and their ability to earn money.

Administrative delays also leave new arrivals largely cut off from the outside world. Mr Atkins noted that vetting visitors and approving telephone numbers can take weeks, recalling that it took him five weeks to see his own son after being jailed.

Brand, who has reinvented himself as a Christian influencer in recent years, will be able to apply to attend weekly Sunday chapel services or request meetings with the prison chaplain.

His imprisonment has also prompted fresh national scrutiny surrounding the country’s television and entertainment industry.

Speaking on Thursday, prime minister Andy Burnham said the media must “look at itself” and “step forward” to ensure women and girls are protected, while culture secretary Lisa Nandy stressed ministers would not hesitate to intervene if industry safeguards fall short.

While Brand is expected to be transferred to a more modern facility with a less severe regime in due course, sentencing guidelines dictate he will serve at least two-thirds of his term – seven years – before becoming eligible.