Specialist teams continued a painstaking search of west London waterways and riverbanks in the hunt for missing Alice Gross and a convicted murderer who is the prime suspect in her disappearance.
Frogmen and officers wearing forensic suits were examining the River Brent and its banks near Ealing Hospital as Scotland Yard carries out the biggest search operation since the July 7 bombings.
The force has come under fire for taking four days to ask Latvian authorities for help in finding killer Arnis Zalkalns, who served seven years in prison after he was convicted of killing his wife Rudite Zalkalns in his native country.
He went missing on September 3, six days after Alice, 14, was last seen walking by the Grand Union Canal in west London on August 28.
She was caught on CCTV that afternoon walking back towards her home in Hanwell, and Zalkalns, who was convicted of murder in 1998, was seen 15 minutes later riding past the same spot on a mountain bike.
He left his passport at his house in Ealing, west London, and police in Latvia confirmed he has not entered the country by plane but conceded it was possible he could have got in undetected if he travelled by car or coach.
It has also emerged he was arrested on suspicion of indecently assaulting a 14-year-old girl in the UK in 2009, but no further action was taken.
The Metropolitan Police said that 600 officers from eight forces have searched 23sq km of open land and 5.4km of canals and rivers in the largest deployment of search assets for an ongoing investigation since the attacks of 2005.
Scotland Yard have insisted they have no evidence to suggest that Alice, who suffers from anorexia, has come to harm.
General labourer Zalkalns is thought to have come to the UK in 2007.