Al Mabhouh was killed in a Dubai hotel room on January 19.
"We have DNA evidence … from the crime scene. The DNA of the criminals is there," Lieutenant General Dahi Khalfan Tamim, Chief of Dubai Police, told Al Arabiya TV on Friday.
The police have so far identified 26 suspects.
"Fingerprint evidence from several suspects has provided 100 per cent proof of the killers' identities," Khalfan said, adding that they have "categorical DNA proof on one of the assassins".
The murder of Mabhouh mounted international pressure on Israel after Dubai said that Israeli agents, most using stolen Western identities, carried out the hit.
But Israel denied any involvement saying there was no evidence that its Mossad spy agency was behind the hit on Mabhouh, one of the founders of Hamas' military wing.
Khalfan said that an international police unit with officers from the emirates and at least seven other countries would hunt for the killers.
Published 27 February 2010, 08:45 IST