An 18-year-old man from Aylesbury was arrested on suspicion of rape yesterday (13 April).
Thames Valley Police confirmed today that the man is still in police custody.
On Monday (April 11) evening between 6:30pm and 7:50pm a teenage girl was raped twice by the same person.
She was attacked both on the third and fifth floor of the car park near Aylesbury Waterside Theatre.
She was in Walton Street car park when she became isolated and was attacked.
Specially trained police officers are assisting the girl.
The authorities are still pleading to anyone with information to assist with their investigation.
People can do this by calling 101 or making a report on the Thames Valley Police website, quoting reference number 43220156535.