Police searching for 14-year-old Alice Gross in London say they have now launched a murder investigation.
It comes after a body, which has not yet been formally identified, was found in the River Brent overnight.
Alice's family has been informed of the latest developments.
Scotland Yard Commander Graham McNulty said, "our work at this scene is crucial to make sure we capture all of the available evidence, to establish who is responsible for this dreadful crime.
He confirmed that "significant efforts were made to conceal the body."
Metropolitan Police previously said their investigation into the disappearance of the teenager from West London has been their biggest search deployment since the London bombings in 2005.
Alice Gross was last seen on the afternoon of August 28th.