DUBAI, Dec 28 (Reuters) - The United Arab Emirates chose to release details of a Hamas leader's assassination in Dubai nearly a year ago, after deciding silence would be seen as siding with Israel, U.S. cables released by WikiLeaks showed.

The assassination of Mahmoud al-Mabhouh in an hotel room -- which UAE police said was very likely the work of Israel's Mossad spy agency -- was carried out in January by a team using forged passports and disguises.

The two options discussed were to say nothing at all, or to reveal more or less the full extent of the UAE's investigations, U.S. Ambassador Richard Olson wrote in a diplomatic cable, citing a conversation with a UAE government media adviser.

Saying nothing would have been perceived as protecting the Israelis, the ambassador wrote. The cables released on the WikiLeaks website show the hit was discussed for nine days at the highest levels before being released to the public.

The statement was carefully drafted not to point any fingers, but the reference ... to a gang with Western passports will be read locally as referring to the Mossad, Olson wrote.

Israel has said there was no proof that its intelligence agency was behind the murder, which eliminated a Hamas leader suspected of smuggling arms into the Gaza Strip.

Dubai officials were not immediately available for comment on the cables.

As Dubai splashed details of the hit, complete with surveillance camera footage and passport scans, a diplomatic row erupted since many of the suspected assassins were travelling on forged European passports.

The cables, written soon after the assassination, do not reveal the identities of the agents. But Dubai's police chief Dahi Khalfan Tamim had said he expected they would show that Mossad was involved in the murder.

The documents will surely prove to those who doubted us, Tamim said, Gulf News quoted him as saying in a report last Friday.