The grandmother of Tia Sharp, who was questioned over the 12-year-old's murder, will face no further action.
Christine Sharp was arrested in August after her granddaughter's body was discovered in the loft of her home in New Addington, south London.
The 46-year-old was questioned by police on suspicion of murder and bailed while inquiries continued.
The Metropolitan Police has now confirmed that she will face no further action.
The disappearance of schoolgirl Tia sparked a huge search around the Croydon area with family members leading the campaign.
Police officers had previously visited Christine Sharp's home, but it was only days into the search that Tia's body was discovered hidden in the loft.
Stuart Hazell has been charged with Tia's murder and has been remanded in custody ahead of a trial scheduled for early 2013.
Another man, a 39-year-old neighbour, who was arrested on suspicion of assisting an offender, remains on police bail until mid-December.