Dubai's police chief said he is almost certain Israel's Mossad spy agency was behind the murder of a Hamas militant at a Dubai hotel, a newspaper reported, raising the stakes in an escalating international row over the killing.

Hamas military official Mahmoud Al-Mabhouh was found dead in his luxury hotel room in January, and the Palestinian Islamist militant group has accused Israel of being behind the killing.

"Our investigations reveal that Mossad is involved in the murder of (Mahmoud) Al-Mabhouh. It is 99 percent, if not 100 percent, that Mossad is standing behind the murder," Dubai police chief Dahi Khalfan Tamim told The National newspaper.   

He was not immediately available to comment on the report.

Israeli Foreign Minister Avigdor Lieberman said on Thursday that there was no reason to believe that Mossad had carried out the assassination.   

An Israeli security source has said Mabhouh played a key role in smuggling Iranian-funded arms to militants in the Gaza Strip and Israel's media have been unanimous in linking Mabhouh to the Gaza arms supply.   

Tamim said Dubai police had evidence linking the suspects in the case to people with a close connection to Israel, the newspaper said in a report carried on its website. But it said Tamim did not disclose that evidence.

The report added that Interpol had issued red notices for 11 suspects wanted in the case. Interpol says a red notice is not an international arrest warrant, but is put out after authorities in a country issue a warrant to help with the identification or location of a suspect with a view to their arrest or extradition.

Mossad is widely believed to have stepped up covert missions against Hamas and Lebanon's Hezbollah militia as well as Iran's nuclear project.

Among killings attributed to Mossad was that of Hezbollah commander Imad Moughniyeh in Damascus two years ago.

Al-Mabhouh, who was born in the Gaza Strip but had lived in Syria since 1989, was killed a day after he arrived in Dubai. Both a Hamas official and Israel have said Al-Mabhouh masterminded the abduction and killing of two Israeli soldiers during a Palestinian uprising in the 1980s. - Reuters