The mother of murdered schoolgirl Lucy McHugh has urged Facebook to provide police with access to the account belonging to the man suspected of killing her daughter.
Lucy, 13, from Southampton, was found in woodland at Southampton Sports Centre after being stabbed to death.
Stephen Nicholson, a family friend who was staying in Lucy’s home until shortly before her death, was questioned on suspicion of murder and sexual activity with a child but twice refused to give detectives his Facebook password.
The care worker, 24, was jailed for 14 months over his refusal to hand over the password to his account.
Stacey White, Lucy’s mother, said detectives could uncover information vital to their investigation if they are allowed to read messages sent and received by Nicholson before the teenager's death.
Investigators now face having to take lengthy legal action in the US in order to obtain access, with the delay branded "deeply disturbing" by the head of the Commons Home Affairs Committee.
Ms White has said unlocking the account would "certainly give police an idea of what was being said between Lucy and Stephen".
"In situations like this, Facebook really should just release the information that is needed and I think that is the opinion that everybody has," she told the Daily Mail.
"They should give over the account details. Lucy needs justice. It's so easy for them to do."
According to prosecutors Nicholson had contact with the teenager as recently as the morning of her disappearance.
Nicholson pleaded guilty to a charge under the Regulation of Investigatory Powers Act (Ripa) before his sentencing at Southampton Crown Court.
The court heard his excuse for refusing access was to protect himself and his family as there was information relating to cannabis on the account.
Prosecutors said police were facing a "lengthy procedure" in order to obtain access and the investigation into Lucy's death had been "considerably obstructed" as a result.
Yvette Cooper, chairman of the Home Affairs Select Committee, called on the Government and Facebook to create a fast legal procedure for such cases.
"This was an appalling murder, and Lucy McHugh's family need justice," she told the Mail.
"For there to be such long delays and cumbersome international processes for getting crucial information in such a serious case is deeply disturbing."
Facebook told the paper it was "co-operating with Hampshire Police".
Nicholson remains on bail for his arrest on suspicion of murder and sexual activity with a child.
A charging decision is anticipated on 27 October.
Agencies contributed to this report
