HUNDREDS of mountain rescue volunteers, dog handlers and police divers have stepped up the hunt for missing five-year-old April Jones as officers continued to question a father of two young girls over her disappearance.

Police insisted the size of the operation sent a signal they were not scaling back the search, as hopes the child might be recovered alive began to fade.

With the search entering a fourth day since April disappeared while playing with friends outside her home in Machynlleth in mid-Wales, the hunt was narrowed to 20 locations, including houses, outbuildings, open areas and river banks around the country town.

Fears for April's wellbeing were heightened after it was revealed she suffers from cerebal palsy and irritable bowel syndrome and is dependent on constant medication.

Mark Bridger, 46, who has two daughters aged seven and 10 and lived just yards from where April was snatched on the Bryn-y-Gog housing estate, remained in police custody.

Police would give no details of what their questioning of Mr Bridger had revealed, but it emerged his children were regular playmates of April, who was last seen willingly climbing into a left-hand driver Land Rover Discovery at around 7pm on Monday.

Neighbours told how the former lifeguard and solider is well-known to adults and children on the Brynygog estate, where April lives. His former wife and three former partners also live in the area. He has a further four children from other relationships and is believed to have lived in Machynlleth for around 15 years.

Police said they had interviewed Mr Bridger twice since his arrest on Tuesday evening and are looking into his past to build up a profile.

They also took the unusual step of issuing images of Mr Bridger and his blue Land Rover Discovery as part of an appeal to track his movements from the time of the abduction to his arrest. They later said this had generated more than 400 calls from members of the public.

Superintendent Ian John said the search for April was growing. He added: "In no way are we scaling back our search and we remain completely focused and committed to finding April."

The force has 100 mountain rescue volunteers, more than 100 police-trained search officers, 20 dog handlers, two boats from the RNLI, a team of kayakers and the force's marine unit taking part in the search. Three UK experts have also been drafted in to help with the hunt.

Meanwhile, April's mother made a desperate plea for help finding her daughter.

Coral Jones, 40, said: "We are desperate for any news. April is only five-years-old. Please, please help find her."

Mrs Jones, who was accompanied by her stepfather, April's step-grandfather, Dai Smith, sobbed as she said: "It's been 36 hours since April was taken from us.

"There must be someone out there who knows where she is and can help the police find her. We are desperate for any news."

Mr Bridger was arrested walking about two miles north of the town by a police patrol. His car was later seized from a repair garage in the town and is being examined by forensics officers.

Mr Bridger's teenage son had joined volunteers in the search.

Scott Williams said he had been estranged from his father for most of his life and only met him a couple of months ago.

He said: "I have only met him on a couple of occasions. It was a shock when we heard he'd been arrested."