A man is being questioned today about the brutal double rape of a teenage girl in Belfast.
He was arrested after detectives raided a house on the western outskirts of the city, near where the assault took place.
The 15-year-old victim, from the north of England, was robbed and attacked by two men last Saturday.
Three teenage boys she was with were beaten, stripped to the waist and forced to watch while she was sexually assaulted twice.
One of the attackers, who was armed with a screwdriver, then called her mother on a stolen mobile phone to gloat over what he had done.
Detectives searched a house in the Twinbrooke area today. A PSNI statement said: "Following the search, one man voluntarily presented himself to Woodbourne Police Station. He was then arrested."
Police said they were now following "definite lines of inquiry" but said there were no further details.
The girl had been holidaying in Belfast and was staying with her three friends at one of their families' homes. Their ordeal began after they sneaked out unnoticed as the parents slept and were confronted by two men near the house.
The girl was dragged into an empty petrol station forecourt on Blacks Road and raped while the boys were battered with an iron bar.
All four were taken to a nearby golfing complex where a second vicious sex assault took place.
At one stage their captors issued a chilling warning, telling them: "This is where it gets messy."
The girl's mother revealed how the attack has destroyed her daughter.
"She's not the same girl we sent over here," she said. "We sent over a lively, confident, bubbly teenage girl. And now she's withdrawn and clingy and scared."