The Foreign Office was investigating how the identities of six innocent Britons at least three of whom lived in Israel came to be used by the alleged hit team.
Hamas, the Islamist group that controls Gaza, blamed Mossad, the Israeli intelligence service, for the killing of Mahmoud al-Mabhouh, who was found dead in a hotel room in Dubai last month.
Israel refused to comment on claims that the 11-strong hit squad were its agents, but any admission that it was behind the assassination would threaten Britains fragile intelligence-sharing agreement with Mossad.
As police in Dubai released CCTV footage of the suspects yesterday, some of the Britons whose identities were stolen voiced their anger after waking up to discover that they had been named in the plot.
"I have not left Israel for two years and I certainly have not been to Dubai recently," said Kent-born Paul Keeley, 42, a builder who has lived on a Kibbutz in northern Israel for the past 15 years.
"When I first heard about this I immediately looked to make sure my passport was still there and it was. It has not been stolen, so I dont know what on earth has happened.
"I woke up this morning and suddenly my life is like an espionage movie. It is all very worrying but I know I have not done anything wrong."