The number of children abducted in Britain and taken abroad illegally has risen by a fifth, to almost 500, since 2005, it has been reported.
Abducted children were most likely to be taken to Pakistan, frollowed by the USA, Ireland and Spain.
Authorities dealth with 336 cases, involving 470 children last year, government figures released under Freedom of Information rules showed.
The most likely cause was marriages breaking down between couples of different nationalities, where the parent without custody took the child.
The summer holidays are the most likely time for children to be abducted, as they are not returned home after visiting a parent.
The most difficult cases involve countries which have not signed up to the Hague Convention, an international treaty in which countries agree to return children wrongfully detained.
Islamic countries are often the most difficult for mothers to get children back if they have been taken by their fathers.
Recently, Gordon Brown and Andy Burnham, the health secretary, intervened in the case of Nadia Fawzi, a British girl taken from Wigan where she lived with her mother, Sarah Taylor, to Libya by her father in 2007.
Mr Burnham, Nadia's MP, flew to Libya to meet authorities there, while the Prime Minister asked Colonel Gaddafi, to help return her to Britain. Miss Taylor has taken her fight to the Libyan courts, and Mr Burnham said he is hopeful Nadia will soon be reunited with her mother.
Mr Burnham said: "This awful injustice and crime has now been raised at the highest level and we now expect swift action. This is a story about a young girl taken illegally off the streets of my constituency and I will go to any lengths to right that wrong."
Denise Carter, director of Reunite, a UK charity specialising in international parental child abduction, said: "The increase in international travel and more and more people travelling on short-term contracts and changing their habitual residence also has an effect."
Foreign Office spokesperson said: "When there is no international mechanism in place, usually the left-behind parent's only option [other than trying to come to an agreement with the other parent] is to file a case in the courts of the country where their child has been taken. However, pursuing such a case will often be expensive and there is no guarantee the courts will decide that the child should be returned to the UK."
Published: 7:00AM BST 10 Aug 2009