Police investigating the disappearance of a 19-year-old woman, who detectives fear has been murdered, have arrested a 22-year-old man.
Jack Wall is being held by Hertfordshire Police after Amelia Arnold went missing. She was last seen on Wednesday.
Wall, of Hadrian's Walk, Stevenage, had been urged to hand himself in to police, who said they would "urgently like to speak with (him) in connection with the inquiry".
Detectives also issued an appeal for sightings of a Citroen Berlingo van as part of the investigation.
As part of the inquiry, detectives and scene-of-crime specialists are examining a property in Hadrian's Walk.
Witnesses who may have seen suspicious activity at the address between Wednesday and Friday are also being asked to come forward.
– DETECTIVE CHIEF INSPECTOR TIM REDFEARN
We've been speaking with residents in Hadrian's Walk but I would like to hear from anyone who has been in the area between these times and believes they may have seen or heard any suspicious activity to make contact with police.
We would also like to appeal to anyone who may have witnessed anyone acting suspiciously in a white Citroen Berlingo, registration R389 VDP, in the Stevenage area since Wednesday.
Any information, however small could prove vital to our investigation.
Meanwhile, a 41-year-old man from the local area has been arrested in connection with the investigation and is in police custody.
Anyone with information which could assist the inquiry is asked to contact police immediately by calling the non-emergency number, 101.
Alternatively, information can be passed on anonymously to the Crimestoppers hotline on 0800 555111.