Detective Chief Inspector Nick Scola apologised to Tia Sharp's family for the fact that police did not find her body in their first two searches of the house Stuart Hazell shared with her grandmother.
The senior investigating officer added that finding it earlier "would not have made any difference" to what happened afterwards, merely brought it forward.
The family would still have had to deal with Hazell's lies and his interest in child abuse and young girls, he said.
"The early searches were really just a look round, they were not deep searches," he added.
In an in-depth interview with ITV's Tonight, Tia Sharp's mother and grandmother tell their harrowing story and speak openly about their loss
The mother of murdered schoolgirl Tia Sharp has said the man responsible for her death "deserves to suffer".
Stuart Hazell, 37, changed his plea to guilty in the murder trial of schoolgirl Tia Sharp claiming her 'family have suffered enough'.