Tamim told Al-Bayan, another Dubai newspaper, that "Dubai police has more evidence, apart from the tapes and photos that were revealed earlier".
"The coming days will carry more surprises which will leave no room for doubt," he said.
Israeli silence on the killing was broken on Wednesday by Avigdor Lieberman, the country's foreign minister, who said that "there is no reason to think that it was the Israeli Mossad, and not some other intelligence service or country up to some mischief".
However, he also said that Israel maintains a "policy of ambiguity" on intelligence matters.
London, Paris and Dublin have all demanded explanations from Israel as to why passport details of their citizens had been used by the suspected hit squad.
Britain summoned Ron Prosor, the Israeli ambassador to London, for a meeting with Peter Ricketts, who heads its diplomatic service, to explain how several UK citizens living in Israel found their passport details had been used by the alleged killers.
David Miliband, the British foreign minister, described the use of six British passports as an "outrage".
Miliband said Ricketts had made clear "how seriously we take any suggestion of fraudulent use of British passports" and sought Israeli assistance.
"We hope and expect they will co-operate fully with the investigation that has been launched by the prime minister [Gordon Brown]," said Miliband, adding that he hoped to discuss the issue further with Lieberman, when both men meet in Brussels on Monday.
Britain's Serious Organised Crime Agency is to lead an investigation into the matter in close co-operation with the Emirati authorities.
Paris also demanded that Israel explain how an apparently forged French passport had been used by the suspected assassins.
"We are asking for explanations from Israel's embassy in France over the circumstances of the use of a fake French passport in the assassination of a Hamas member in Dubai," said the country's foreign ministry.
Dublin followed suit, calling in the Israeli ambassador to grill him about how the suspects had used passport details of three Irish citizens, one of whom has never visited Israel.
Sources within Hamas, which has already blamed Israel for being behind the killing, have also accused members of a rival Palestinian faction of helping Israel to kill al-Mabhouh.
The sources accused members of Fatah party, headed by Palestinian president Mahmoud Abbas, of aiding the murder.
In the Gaza Strip, the Palestinian territory run by Hamas, anger spilled onto the streets on Wednesday with thousands of people gathering at a rally vowing to avengethe death of al-Mabhouh.
|Al-Mabhouh was one of the founders of Hamas' armed wing [Reuters]
Al-Mabhouh was a senior commander and one of the founders of the Ezzedine al-Qassam Brigades, Hamas'
Khaled Meshaal, Hamas' leader and himself a victim of an attempted Israeli assassination, pointed the finger of blame squarely at Mossad.
"The time for promises and talk of revenge is done. Now is the time for action," he said, addressing the Gaza rally via video from Damascus, where he is based.
Israeli media has seen mixed reactions, with some praising al-Mabhouh's death, and others criticising a sloppy operation.
A front-page commentary in the daily newspaper Haaretz called for Meir Dagan, the head of Mossad, to be removed from office.
But a source close to Dagan told the Reuters news agency that the intelligence chief has no intention to resignbefore the end of his term later this year.
For Dagan to resign on the heels of a political row over al-Mabhouh's death would be to admit having had a role in it, the source said.