Update, Oct. 28, 5:55 pm. Interview postponed, indefinitely. Read more here.

The half-brothers of Lisa Irwin, who said they heard noises the night the 11-month-old baby disappeared, will be questioned for a second time by a child service specialist working with the investigation.

Lisa's parents Deborah Bradley and Jeremy Irwin each have a son from a previous relationship. The boys, ages 5 and 8, live in their Kansas City. Mo., home. Both were briefly interviewed by a social worker in the immediate aftermath of their half-sister's disappearance.

Bradley told NBC last week that the boys heard noises the night Lisa vanished, but she was hazy on the details.

They said they heard noises (the night Lisa disappeared), Bradley said. I don't know if that was before we went to sleep or after. Bradley said she has not pressed the boys on the issue because she didn't want to put them through anything else.

Kansas City police Capt. Steve Young told CNN that the boys would be interviewed by a child services specialist trained to interview kids, and that no police would be present during the questioning.

Not an interrogation, Young said. They are kids, after all.

Young has said that Bradley and Irwin have refused to be interviewed separately, despite appeals for unrestricted  interviews.

We want to know what they have to say on their own, the Kansas City Star quotes Young saying on Tuesday.

Joe Tacopina, a lawyer for the couple, told ABC he has imposed restrictions on police access to Lisa's parents, due in part to the actions of police in the wake of the baby's disappearance.

Oh, there's a restriction, Tacopina said. I'm imposing that the questioning is going to be in good faith and fair and not the questioning that was done within an hour of baby Lisa's disappearance.

There is a conflict between the role of the police to close a case and bring folks to justice and the rights of the innocent to avoid being railroaded, lawyer Dan Ross told the Kansas City Star. The legitimate purpose of an investigation can be met without threatening a client's rights against self-incrimination.

Bradley has said she felt police were treating her as a suspect from the start, and reportedly told her she failed a lie detector test.

That's just not good investigatory tactics and it doesn't build good faith in them, Tacopina said, adding that the couple will agree to be interviewed as long as the investigators doing the questioning are ones who have not previously determined guilt before having a stitch of evidence. We want a fair investigation.

 Bradley has changed the initial story she gave investigators, updating the time she claimed to have last seen her daughter. Initially, Bradley said she checked on Lisa at around 10:30 p.m. on Oct. 3, but later said she last saw her daughter when she put her to bed around 6:30.

Bradley has also admitted to drinking several glasses of wine the evening of Oct. 3 - enough to be drunk and possibly enough to have blacked out.

Lawyers for Lisa Irwin's parents are urging investigators to aggressively follow eyewitness reports of a man seen near Irwin's home carrying a baby in a diaper the night she disappeared, in addition to surveillance footage of a man walking past a gas station two miles from the home at 2:15 a.m. Oct. 4.

That should raise all the red flags that it raises in my head to anyone who's out there really trying to do an investigation that includes a hunt for Lisa, and hopefully an alive and well Lisa, Tacopina told ABC.

On Friday, a cadaver dog brought into search the family's home indicated positive 'hit' for the scent of a deceased human in an area of the floor of Bradley's bedroom near the bed, according to a police affadavit.