A 46-year-old man has been arrested as part of the police investigation into the hunt of missing five-year-old April Jones.
Detective Superintendent Reg Bevan, from Dyfed Powys Police, said he was arrested in the Machynlleth area within the last hour.
April was last seen by another child getting into the driver's side of a grey van which drove off in the Mid Wales town of Machynlleth at about 7pm last night.
Police say they are still treating the investigation on the basis that April is still alive.
Mr Bevan said: ''Within the last hour we have arrested a 46-year-old male from the Machynlleth area who is being detained at Aberystwyth police station.
''We made the arrest just outside Machynlleth and we are hopeful that this individual will assist us in locating April, who is still missing.
''We are still pursuing all lines of inquiry with a view that April is still alive and we will continue to do so until we find her.''
He added that the man was arrested while he walked about just outside outside Machynlleth.
The detective added: "We knew who we were looking for."
He said that officers had also seized a vehicle.
The investigation remains ''fast-moving'' and he said he may have a further update later.
Meanwhile Superintendent Ian John added: ''We are continuing our search for April and that continues, as our priority is to find her and bring her home to her family.
''I want to take this opportunity to thank everyone who has assisted us in this search.''
He paid tribute to the local community, British Transport Police, officers from surrounding forces and offers of support from forces around the UK, including the Metropolitan Police, saying it was ''the police family really pulling together to try and find April''.
He also thanked Aberdovey and Brecon mountain rescue teams.
A long stretch of the A487 from Machynlleth northwards has been closed in both directions as part of the investigation, police said.
The Traffic Wales website said the area around the Dyfi bridge would be closed ''until further notice''.