Two women were raped at the 2016 Reading Festival, police say.
Thames Valley Police are investigating the separate attacks, which involved a 17-year-old and a 28-year-old.
A 22-year-old man has been arrested on suspicion of rape by detectives investigating the attack on the older woman.
About 90,000 people attended the three-day festival. Police received 117 reports of crimes, a 20% drop on the previous year.