Foreign Secretary David Miliband has urged Israel to co-operate in a British investigation into the use of faked British passports in an alleged Mossad assassination.
After a private 45-minute meeting with Israeli foreign minister Avigdor Lieberman in Brussels, Mr Miliband said he had received no new information about possible Israeli involvement.
But he added: "I set out the seriousness of the issue to Britain and the need for Britain and Israel to co-operate, and the importance of the investigation the Prime Minister has announced and the importance we attach to Israeli co-operation with that investigation.
"It is very important that people know that we continue to take this issue very seriously indeed."
He urged Israel to co-operate in a "transparent and clear" way.
But he admitted that Mr Lieberman had not resolved the question of who was behind the assassination.
"Mr Lieberman said he had no information at this stage," said Mr Miliband.
Earlier, Home Secretary Alan Johnson confirmed, in a written statement to Parliament, that the Serious Organised Crime Agency was investigating the "apparent use of counterfeit passports" by the hit squad.
What role, if any, Israel played in equipping the hit squad with faked British and Irish passports as part of the murder of a Hamas leader in a Dubai hotel is unclear.