A former inmate who later worked at HMP Birmingham has described the "anarchy" and "chaos" at the privately-run prison, which is being taken over by the Government after ministers concluded "drastic action" was needed to address failings at the jail.
After serving time at the prison, Tanayah Sam later returned in a role that saw him mediate between prisoners and staff.
Mr Sam told ITV News conditions at the prison declined following a positive inspection in 2014, which resulted in management "taking their eye off the ball" and experienced staff being replaced with "naive" employees.
And he singled out a lack of money for simple items such as cleaning products as symptomatic of the disconnect that became so extreme between the inmates, staff and prison hierarchy.
"They're not feeling as though they're part of a society, so what we see as a result is violence, anarchy, chaos and that's where we've got to today," he told ITV News.
- Video report by ITV News Correspondent Angus Walker
Asked what conditions were like day to day in the prison, Sam told ITV News: "Ultimately, prisoners will be out of their cells, nothing to do, so they're just hanging around and the devil makes work for idle hands, so the criminal underworld will thrive in such environments, the vulnerable will be sought and most definitely will suffer injury.
"The staff will be standing back, they would see (what's happening), but they would be standing back as they don't feel the power to do anything.
"So, as you can imagine, there's violence, there's drug taking, sexual assaults have increased since 2012 in prisons, attempted hangings, hangings, violent crimes with weapons."
Problems started under G4S, who were in charge of running the prison, following a positive report into jail in 2014.
"When they got their inspection in 2014, which showed quality of life for both prisoners and prison staff had improved, management took their eye off the ball, foot off the gas and their focus went elsewhere," Mr Sam said.
Asked why attitudes worsened in the prison, he said: "Because draconian measures are still in place; there's no innovation.
"This is 2018, right? Although they're in prison and done a crime so they've got to serve their time, we've got to build up these individuals, to come out of prison and engage back into society.
"And when those individuals in prison are feeling not only isolated and their voices are being lost but also the staff who are overseeing them don't feel empowered in any way as there's no purposeful activities as such, it's going to get worse and worse and worse and management focused on other areas rather than the prisoners' voices.
"The prisoners' voices and the staff's voices and getting them to sit round the table and work together, because that's what it could have been, a cohesive prison, as that's what I first saw from G4S from 2012 up to 2015."
- Chief Inspector of Prisons, Peter Clarke
The turnover of staff also caused problems for the jail, according to Mr Sam, who said experienced prison officers were replaced with naive ones who could be influenced by the inmates.
"The prison staff were, ultimately, there to collect a cheque at the end of the month," he said. "The experienced prison staff and the prison staff who had built relations with some of those repeat offenders over the years, they had left.
"So then what you've got is a bunch of new staff who are inexperienced, not just in the work, but inexperienced in life because they're so young.
"They're supposed to be overseeing grown men who for some of them are career criminals.
"It doesn't take a genius to see that there's going to be manipulation, there's going to be corruption. I'm not pointing the finger to say it's solely on corruption but things will happen and increase naturally in such environments."