Police are "in no way scaling back their operation" in the search for April Jones and remain "completely focused and committed" to finding the five-year-old alive, officers said on Wednesday evening.
Detective Superintendent Reg Bevan from Dyfed Powys Police said information about arrested man Mark Bridger, 46, and his blue Land Rover Discovery remains important, but there are various other leads.
He said they have interviewed the 46-year-old twice and are looking into his past to build up a profile.
Rescue team search for missing girl April Jones near Machynlleth
Bevan said: "While these are clearly a significant line of inquiry, I must emphasise that there are many other leads that we are actively pursuing in an effort to find 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.
Bridger was walking in the direction of Machynlleth when he was detained by police
Three UK experts have also been drafted in to help with the hunt.
The force has received more than 400 calls since making an appeal for information earlier today and is focusing on 20 scenes including houses, outbuildings, open areas and riverbanks around Machynlleth.
Superintendent Ian John said the search for April was "continuing to grow and grow at quite a pace".
April Jones has been missing since Monday
Asked what he thought the likelihood is of finding April alive, Mr John said: "Our efforts are completely focused on doing that and we will continue to do that. I don't want to speculate and put any kind of time limit on that."
The focus of the interviews with Mr Bridger has been trying to find any information about where April is, Mr Bevan said.
The senior officer would not reveal what the 46-year-old had said to avoid jeopardising the search.
He told reporters: "He has been interviewed twice. Clearly, our focus in those interviews, as it is in this whole inquiry, is to find April. That is primarily what we've been discussing with him.
"What I don't want to do is compromise the investigation or any chance of finding April, so unfortunately I can't divulge exactly what he's told us so far."
April has been missing since around 7pm on Monday when she vanished while playing with friends in the Bryn-y-Gog estate. She was seen getting into a vehicle, apparently without a struggle.
Coral Jones made a heartfelt plea for information for her daughter
Since then, hundreds of people from the local area and further afield have helped search for the little girl, but police have now urged them to allow specialist teams to take over.
The mother of missing five-year-old April Jones made an emotional appeal for information during a press conference on Wednesday afternoon.
"We are desperate for any news. April is only five years old. There must be someone out there who knows where she is. Please, please help find her," a tearful Coral Jones said.
Jones, who collapsed into tears after giving her statement, was comforted by her stepfather Dai Smith. Her daughter has now been missing for almost 48 hours.
Detective Superintendent Reg Bevan also repeated an appeal for anyone who may have witnessed Bridger or his distinctive blue LandRover Discovery, with the registration number L503 MEP.
Police also issued a picture of the 46-year-old and his car, which is currently being examined by forensics.
April's godmother Mair Raftree, 41 told Sky News "Like we heard this morning, the police said they didn't need any volunteers. But I couldn't sit at home Aberystwyth, I had to come.
"Her mum, her dad, her grandparents are all devastated. They just want her back."