The number of "dangerous parents" fleeing with their children when social services become involved in their families is increasing, a senior British judge has warned.
Lord Justice Thorpe, head of a UK help desk for lawyers involved in international abductions and child custody cases, said that in one case, two young children were found living in a makeshift shelter near live railway tracks after being brought to the UK from Poland.
Most of the parents involved have links to Eastern Europe and, with almost two-thirds of children born in London in 2010 having a foreign parent, there was "the potential for significant future growth" in cases, the judge said.
In the Polish case, the children were brought to the UK by their father and uncle, despite the fact that Polish social services had a care order for them.
They were taken into police protection after being found living by the railway tracks four days after arriving in the UK after travelling by road and rail across Europe.
But a breakdown of communication between the English and Polish social services meant it was unclear whether the children should be returned to Poland and under what conditions.
Lord Justice Thorpe, head of International Family Justice (IFJ) for England and Wales, and the centre's lawyer Victoria Miller were called in to help sort out the case.
"The tendency of dangerous parents to bolt when social services are exercising legitimate protective powers is all too common," the judge said.
"We are seeing a rising number of these types of cases being referred to the office, mostly involving Eastern European countries."
Figures published in the IFJ's annual report for 2011 showed the number of cases in which the centre has intervened increased from just 27 in 2007 to 92 in 2010 and 180 last year.
There are no published figures for the growth in international litigation overall.