Prime Minister Gordon Brown has asked Libyan leader Muammar Gaddafi to intervene in the case of a British child abducted by her Libyan father and taken to his country.
Britain is seeking the repatriation of six-year-old Nadia Fawzi, who was taken from her mother Sarah Taylor, of Wigan, in 2007.
Mr Brown raised her case when the two leaders met at the G8 summit in L'Aquila, Italy, and told Colonel Gaddafi that Britain wanted Nadia to be returned to the UK to be reunited with her mother.
Gaddafi undertook to look into the case and see what he could do as soon as possible, said a Downing Street spokesman.
Mr Brown and Col Gaddafi met ahead of talks between the G8 states - Britain, the US, France, Germany, Italy, Japan, Canada and Russia - and African leaders on measures to improve food security in the world's poorest countries.
The G8 are expected to promise 15 billion US dollars (£9.2bn) in aid for agriculture and food infrastructure.
The meeting is the first time Mr Brown has met Col Gaddafi, who was an international pariah for years following the Lockerbie bombing, for which Libya was blamed.
His predecessor Tony Blair famously flew to Libya in 2004 to meet Gaddafi in his desert tent after he had given up his weapons of mass destruction capability and accepted responsibility.
Mr Brown reiterated his "admiration and gratitude" for Col Gaddafi's "brave" decision to scrap WMD programmes in 2003.
In an apparent reference to Iran and North Korea, Mr Brown said that in the context of a nuclear non-proliferation summit called by US President Barack Obama for spring 2010, it would be necessary to try to persuade other countries to follow Libya's example.
