Alice suspect murdered his wife
A Latvian builder named as the prime suspect in the search for schoolgirl Alice Gross was convicted of murdering his wife, police said.
Scotland Yard said it was looking for Arnis Zalkalns, 41, after he was identified in CCTV around the tow path where Alice went missing.
Toms Sadovskis, a Latvian state police spokesman, confirmed that Zalkalns had served a custodial sentence after he was convicted of killing his wife in his country in 1998.
Mr Sadovskis said he was unable to confirm any other details related to the case.
Zalkalns went missing a week after Alice was last seen on August 28, when she was spotted on CCTV by the Grand Union Canal in west London.
It emerged today that he was arrested on suspicion of indecent assault on a 14-year-old girl in 2009, but no further action was taken in that case.
Scotland Yard today insisted they have no evidence suggesting Alice, 14, who suffered from anorexia, has come to harm.
Detective superintendent Carl Mehta, from the Met's Homicide and Major Crime Command, said: "This is not a murder inquiry in the sense that we don't have any evidence or information to say that Alice is not alive."
Scotland Yard have said it is their understanding that there was no record in the UK of Zalkalns' murder conviction.
Police were told about the conviction in the "last few days" but were unable to provide further details at this stage, Mr Mehta said.
Zalkalns, who works as a general labourer at a building site in Isleworth, west London, is thought to have come to the UK in 2007 and lives with his partner and their young child.
He became a person of interest on September 12 but had come to the notice of police before that, Mr Mehta said.
Police first appealed to the public for help in tracing him on Tuesday after establishing that he cycled along Brentford Lock to go to and from work.
He was seen there on CCTV at 4pm on August 28, 15 minutes after Alice walked the route.
Detectives believe he is likely to have seen the schoolgirl as they were both going north along the canal towpath.
Since Zalkalns was last seen at his home in Ealing on the evening of Wednesday September 3 he has not accessed his bank account or used his mobile phone. His passport was left at his house.
His friends and family have told police that his disappearance is out of character.
Asked if he posed a threat to the public, Mr Mehta said: "I think given what we are finding out about his antecedents and his history, clearly he potentially poses a risk to the public.
"I would ask if anyone sees him not to approach him but to immediately dial 999 and contact the police."
A reward of up to £20,000 is being offered for anyone who has information that leads detectives to find Alice.
Mr Zalkalns is described as white, 5'10", of stocky build and with dark brown hair that he normally wears tied in a pony tail. He is thought to be from Riga, the Latvian capital.
He rides a red Trek mountain bike and was reported missing by his partner at midday on Friday, September 5.
Forensic searches continued today at his home address in a leafy suburban road in Ealing, west London.
Alice's last known movements were between 1pm when she left her Hanwell home and 4.26pm when she walked along Trumpers Way, towards Hanwell.
Her Vans rucksack was found by the River Brent a week and a half ago, but no money or purse was inside and her white iPhone 4S with a distinctive cracked case has yet to be found.
Officers have said her missing smartphone may hold "key" information about her disappearance. The device last connected to the network at just after 5pm on August 28.
A couple saw Alice's bag on August 28 at about 8.15pm on the footpath that runs besides the River Brent between Hanwell Bridge and the Grand Union Canal.
No evidence has been found to suggest she was bullied on social media but police said they hoped finding her phone might uncover any secret communications she might have had.
A 25-year-old man arrested on suspicion of murder on September 6 was told he faces no further action.
A 51-year-old man, who was arrested by officers on suspicion of murder on September 7, was released with no further action the following day.
It is understood border officials can deny foreign nationals entry into the UK if information is received that they pose a genuine threat to the public.
Without that information, however, nationals from EU countries are unlikely to be refused admission to the UK.
The entry of an EU national who has served a custodial sentence for murder would be judged on a "case by case" basis, a source said.
A Home Office spokesman said: "We do not routinely comment on individual cases.
"We have detailed arrangements in place to identify people of concern entering the UK. All passengers are checked against police, security and immigration watch lists and where we are aware of individuals who pose a risk, Border Force officers can - and do - refuse them entry."
Scotland Yard said later that to obtain the full file in relation to the conviction of Zalkalns, it needed to submit an international letter of request via the Crown Prosecution Service for assistance from Latvia.
A spokesman said: "This continues to be a fast moving and ever expanding investigation. As with all live investigations there is information that the police have that they cannot and should not make public."