Interpol has called the 16 additional people, also believed to have entered Dubai on false passports, a secondary group. They are said to have aided the hit squad who suffocated Mr Al-Mabhouh in his hotel room.
Eight of the people named on the passports used by the assassins are British. Six are known to be olim, who made aliyah to Israel in recent years.
Police Chief Dhahi Khalfan Tamim has staked his job on his belief that Israeli intelligence agency Mossad are behind the killing of Mr al-Mabhouh.
As a senior member of Hamas, Mr al-Mabhouh was responsible for the kidnap and murder of two Israel soldiers.
Mr Tamim said: "I challenge Israel to bring the suspects here in order to undergo a DNA test and compare them with the samples we have.
"If it turns out that the results do not match, I will resign. You can lie about anything, but not about DNA.”
