Wiltshire Police is appealing for witnesses following an incident in Castle Street, Salisbury.
Shortly after 4.35 pm on June 3rd, a 17-year-old girl was outside Tesco when she was sexually assaulted by a man.
In a statement, Wiltshire Police said, "We are keen to hear from anyone who witnessed the incident or any local business who may have CCTV footage which could assist our investigation.
"A man in his 40s has been arrested on suspicion of sexual assault and is currently in custody in Melksham for questioning.
"Anyone who can help should call 101 and quote crime reference number 54240064350.
"Alternatively, call CrimeStoppers anonymously on 0800 555 111."