Some prisons refusing to hand out condoms - Hardwick
2 July 2013 Last updated at 16:26 BST
The chief inspector of prisons in England and Wales, Nick Hardwick says some jails are not providing inmates with condoms.
Sex is not allowed in prison but former prisoners and reform groups say it is widespread and mostly unprotected.
Mr Hardwick says sexually transmitted infections caught behind bars could be passed on to the general population.
One man, who asked not to be named, told Newsbeat's Sima Kotecha he was locked up for more than three years. He said: "I was having a lot of gay sex in prison. I reckon more than 100 times and all of it was without a condom because I didn't want to go and ask for a condom.
"To ask for a condom would be outing myself and the person I was about to have sex with and I'd be breaking prison rules."
Nobody from the government would give Newsbeat an interview but former Conservative prisons minister, Crispin Blunt, said the data he had seen did not suggest there was a serious health problem in prisons due to unsafe sex.