All three women live on Dewsbury Moor estate, West Yorks, with mother-of-two Amanda Hyett  next door to the property where Shannon lived with her mother Karen Matthews, 32, and supermarket fishmonger Craig, 22.

Detectives also visited the Hyett home where they are understood to have conducted an “informal chat” with Amanda’s 36-year-old husband Neil.

Despite making the arrests less than 24 hours after Shannon’s mother made her first court appearance since being charged with perverting the course of justice and child neglect, police played down the significance of the “procedural” move.

A source said: “We know who the main players are but we are attempting to tie up every loose end. The problem we are having is that as we get the answer to one question a dozen more seem to emerge.”

Last night Caroline Meehan’s boyfriend Rob Baines, 29, denied his partner had any involvement in Shannon’s disappearance. “She will answer any questions they put to her and will only tell the truth because she has got nothing to hide,” he said.

Matthews last night continued to be under constant watch at New Hall prison in Wakefield where she is being held on remand after being refused bail for her own safety.

It is alleged that the mother-of-seven lied to police and failed to tell them that her daughter was at the flat of 39-year-old Donovan – her boyfriend’s uncle – with whom she had been planning to live.

Craig Meehan is due to appear before Leeds Crown Court today over child porn allegations. 

Police last night called for calm at a public meeting with members of the community who had joined the massive manhunt for Shannon.

But talking about Shannon’s boarded-up family home one resident said: “I’ll be surprised if that house is still standing by the end of the week. There are a lot of angry people around here.”