The police chief of Dubai has told a newspaper he received death threats from Israeli spy agency Mossad, after leading an investigation that fingered Mossad for killing a Hamas leader in the Gulf Arab emirate.

Dubai's police chief, Dahi Khalfan Tamim, led the probe into the killing of Mahmoud al-Mabhouh, who was killed in a Dubai hotel in January. The investigation was unusually public for the region and made Tamim a hero in the Arab world.

Open gallery view Suspects in Dubai assassination of Hamas operative Mahmoud al-Mabhouh

Tamim's revelations about the suspects in a series of press conferences and media interviews - that the hit squad used fake passports from Britain, Ireland, Germany, France and Australia - strained Israel's relationship with several countries.

In an interview published on Thursday, Tamim told United Arab Emirates government-owned daily al-Ittihad he believed Mossad was behind two threats he had received, one in an e-mail and the other in a phone call to one of his relatives.

He said Dubai police had managed to track the email's source, but gave no more details. The e-mail said: "Protect your back if you are going to keep your tongue loose."

In the phone call, his relative was told to pass on a message for Tamim "to remain silent". The paper said the call was made by a "dual nationality Westerner, who was later confirmed to be a retired Mossad agent."

Israeli officials were not available for comment on Thursday due to the Jewish holiday of Simchat Torah.

Israel has neither confirmed nor denied any role in the assassination of Mabhouh. Residents of Israel with the same names as the suspects, holding dual nationalities, said their identities appeared to have been stolen.

The apparent passport abuse drew global criticism. Ireland, Britain and Australia expelled Israeli diplomats.