Dubai police have released CCTV footage of the suspected killers
Police in Dubai are to issue arrest warrants for 11 "agents with European passports" suspected of assassinating a top Hamas official last month.
Mahmoud al-Mabhouh was murdered in his hotel room in Dubai on 20 January.
Reports have suggested that he was in Dubai to buy weapons for Palestinian Islamist movement Hamas. It has accused Israeli agents of killing him.
Dubai's police chief said six of the suspects had British passports, three were Irish, one French and one German.
The Britons were named as James Leonard Clarke, Stephen Daniel Hodes, Paul John Keeley, Michael Lawrence Barney, Jonathan Lewis Graham and Melvyn Adam Mildiner.
One of the group was a woman with Irish papers in the name of Gail Folliard. The other Irish suspects were named as Kevin Daveron and Evan Dennings.
The Foreign and Commonwealth Office and their Irish counterparts have said they are investigating.
Officials in Dubai said the team appeared to be a professional hit-squad, most likely sponsored by a foreign power, suggesting the team were operating on false documents.
He showed CCTV footage of the group entering the hotel where Mr Mabhouh was staying.
At one point the men appear to don wigs and false beards.
"We do not rule out the involvement of Mossad (the Israeli secret service), but when we arrest those suspects we will know who masterminded it," Lt Gen Dhafi Khalfan Tamim said.
"We have no doubts that it was 11 people holding these passports, and we regret that they used the travel documents of friendly countries," Lt Gen Tamim said.
Lt Gen Tamim said the identities had been passed on to Interpol, as part of an official request for international arrest warrants to be issued.
Mr Mabhouh was electrocuted and suffocated, according to reports last month.
Lt Gen Tamim said the suspects had followed Mr Mabhouh into Dubai from Syria, where he lived since 1989, before fanning out to stay at different hotels to avoid detection.
Two Palestinians who aided the team have been arrested, the police said.
Mr Mabhouh was a founder member of the Izzedine al-Qassam Brigades, and was thought to be behind the kidnap and murder of two Israeli soldiers in 1989 during the first Palestinian Intifada.
The Izzedine al-Qassam Brigades have been responsible for suicide bombings and rocket attacks across Israel.
Israel has refused to comment on the accusations its security forces were behind the killing.