Harrowing details of Milly Dowler's final hours as she was raped and murdered by Levi Bellfield have emerged in a statement from her family.
The Dowlers revealed they were made aware of the extent of the 13-year-old's suffering in May last year but were obliged to remain silent for eight months while investigations continued.
In the statement, they said they hoped her soul could "finally rest in peace".
Bellfield gave details of Milly's 14-hour ordeal to police last year.
Last month, Surrey Police said serial killer Bellfield had admitted the schoolgirl's abduction, rape and killing for the first time.
The family said they were issuing the statement because they believed what had been revealed so far did not reflect Bellfield's "true heinousness" to the general public.
"We believe that they should know what Bellfield did to our beautiful daughter and sister Milly," the Dowlers said.
They said 47-year-old Bellfield abducted Milly and assaulted her at his flat near Walton station.
He then drove her to his mother's house and raped her.
After this the killer took Milly to another location where her rape and torture continued, until he strangled her the following day.
The teenager's body was found in September 2002, six months after her murder, in a wood in Yateley Heath, Hampshire - 25 miles from Walton-on-Thames. Experts could not say how she died.
The family also revealed that when Bellfield asked to speak to police about the crime he said he would only talk to female police officers.
Bellfield was given a whole-life prison sentence in June 2011 for Milly's murder.
At this point Surrey Police apologised to the Dowlers for the force's failings in the aftermath of Milly's disappearance. Bellfield - who already had a long criminal record, including for violence - lived along the route the teenager took the day she disappeared, yet although it is claimed officers knocked on his door 11 times they got no reply and he was never questioned.
He was already in jail for the murders of Amelie Delagrange, 22, and Marsha McDonnell, 19, and the attempted murder of Kate Sheedy, 18, when he went on trial accused of killing Milly.
The Dowlers said police shared the details of Milly's ordeal with them last May because the information could have become public - Bellfield had talked to another inmate who was due to be released.
A few days after the family were informed about what had happened to Milly, they said they then heard from Surrey Police that reports of an alleged accomplice were being investigated.
They said learning about Milly's final hours was shocking enough, but the revelation that another person could have been involved was devastating.
The family said they had to remain silent for eight months, but when police finally arrested the suspected accomplice, the person was questioned and released in less than 10 hours because there was no evidence.
The Dowlers said they were left under "unimaginable" pressure and had "had to fight every step of the way".
Their desperation led to a meeting with Home Secretary Theresa May in November.
The statement ended: "Now we know the final hours of Milly's life, perhaps her soul, at long last, can finally rest in peace.
"The general public have always played a huge part in supporting us, for which we are eternally grateful and thankful."
Surrey Police said they had been in regular contact with the Dowler family during the investigation into the circumstances surrounding Milly's murder.
A spokeswoman for the force said: "We recognise this continues to be extremely distressing and our thoughts remain with them."
Bellfield, who now calls himself Yusuf Rahim, lived 50 yards from where Milly vanished but did not become a suspect until he was arrested by police in London for the other offences in 2004.
Police are looking into a number of other crimes in which he is a suspect in the wake of his confession.
When Bellfield was convicted in June 2011, detectives said they believed he could have been responsible for about 20 attacks on women that were never solved.