A Hamas leader killed in a Dubai hotel room was drugged before being suffocated, police have revealed, giving further details of a killing that has led investigators to Britain, Ireland, Germany and Israel.

Dubai Police issued a statement on Sunday saying Mahmud al-Mabhouh was sedated, possibly to make his death appear natural.

Major General Khamis Mattar al-Mazeina, the deputy commander of Dubai police, said: "The killers used the drug succinylcholine to sedate al-Mabhouh before they suffocated him.

"The assassins used this method so that it would seem that his death was natural," the statement said, adding that "there were no signs of resistance shown by the victim".

Israel blamed

Dhahi Khalfan, the Dubai police chief, renewed his accusation that the Israeli spy agency Mossad was responsible for carrying out the crime.

He called on Meir Dagan, who head's Mossad, to step forward and accept responsibility.

"Dagan, the boss, should admit the crime ... or present a categorical denial," the government daily Emarat Al-Youm quoted Khalfan as saying.

"But [Dagan's] current attitude shows he is afraid. Let him be a man, and tell the truth," Khalfan said.

Israel has neither confirmed nor denied any role in the murder, though it knew al-Mabhouh played a role in securing arms for the Palestinian authority in Gaza.

Succinylcholine, also known as suxamethonium, is used to induce muscle relaxation and is favoured by anaesthetists and emergency doctors because it quickly takes effect.

Al-Mabhouh, one of the founders of Hamas' military wing, was found dead in his hotel room on January 20.