Four people arrested in connection with the disappearance of 15-year old Lee Boxell have been bailed.
Murder cops arrested three men and a woman in connection with the 26-year-old mystery yesterday.
A 78-year-old man and a 52-year-old man were arrested on suspicion of murder, conspiracy to pervert the course of justice and indecency with children.
A 42-year-old woman was arrested on suspicion of conspiracy to pervert the course of justice and indecency with children and a 41-year-old man was arrested on suspicion of murder and conspiracy to pervert the course of justice.
All have been bailed to return to a central London police station on June 17.
Lee was last seen in Sutton town centre in September 1988. Police believe his disappearance could be connected to paedophile activity at an informal youth club known as the Shed based at St Dunstan's church in Cheam.
Lee's parents Peter and Christine Boxell
Lee's dad Peter has praised police for their work in bringing the investigation to this stage.
He said: "I'm pleased but we don't know what will happen next. I just hope they can bring our search to an end.
"A few years ago I wouldn't have believed that we could get to this stage but the police have never given up their search.
"They are such a dedicated team - I couldn't ask for a better team than are working on this case. They've left to stone unturned."
The four people arrested were taken to police stations in central London where they remained in custody yesterday.