A 13-year-old girl who left the UK on a Eurotunnel train may have travelled to Poland with her mother’s friend, police said.
Serena Alexander-Benson was last seen by her father leaving her home in Wimbledon at about 07:50 BST on Friday.
She was wearing her green school uniform and told him she was going to school, but did not arrive.
The girl travelled with a female friend of her mother’s – a Polish national living in London – police said.
Scotland Yard said that although Serena lives with her father in London, her mother lives in Poland.
Details of the route Serena and the woman took via Eurotunnel at Folkestone, Kent, are not being released by police.
A spokesman said: “At this stage, the priority of officers is to confirm Serena’s exact whereabouts and confirm that she is safe.
“Any potential offences will be considered in due course.”