KUALA LUMPUR • Dr Fadi al-Batsh, a well-liked electrical engineering lecturer and devout family man, always had a smile for his friends and students in the seven years since he moved to Malaysia from his native Gaza.
Last Saturday, as he walked outside his apartment building in suburban Kuala Lumpur, he was gunned down in a hail of at least 14 bullets by two men on a motorcycle.
It was the Palestinian man's undercover job - as what intelligence officials described as a technology expert for the military wing of the Gaza-based Hamas movement - that had put him in the cross hairs.
Malaysian officials said the attackers were "most likely born in the Middle East or in the West" but would not directly say who they thought was behind the killing.
Dr Fadi's family blamed Mossad, the Israeli spy agency.
That claim has been confirmed by Middle Eastern intelligence officials, who said the killing was part of a broader operation ordered by Mossad chief Yossi Cohen to dismantle a Hamas project that sends Gaza's most promising scientists and engineers overseas to gather know-how and weaponry to fight Israel.
Dr Fadi, who in 2013 co-wrote a paper on drone applications, had been sent there to research and acquire weapon systems and drones for Hamas, the intelligence officials said, speaking on condition of anonymity to discuss a classified programme.
Mossad has been particularly interested in Hamas' advances in unmanned aerial and underwater vehicles, the officials said, which could be used to attack Israeli targets more effectively than the rockets Hamas used during its last wars with Israel.
Israel has distanced itself from allegations that it was responsible for Dr Fadi's death. Defence Minister Avigdor Lieberman blamed the assassination on internal rivalries within the Palestinian leadership.
The killing of Dr Fadi, 35, in the Kuala Lumpur suburb of Gombak, known locally as Little Arabia, is bringing to light not only the increasing presence of Hamas and other groups here, but also Malaysia's emergence as an epicentre of international intrigue.
This was the second high-profile assassination in the Malaysian capital in little more than a year.
In February last year, Mr Kim Jong Nam, the half-brother of North Korean leader Kim Jong Un, was killed at Kuala Lumpur International Airport by two women who prosecutors said smeared a nerve agent on his face.
The women, from Indonesia and Vietnam, are on trial for his death, but at least seven North Koreans suspected of being linked to the killing escaped or were allowed to leave the country, officials said.
Malaysia is also known as a port for contraband, ranging from North Korean weapons to endangered animal products and illegally felled trees.
Malaysia's government has for decades been sympathetic to the Palestinian cause: It has no diplomatic relations with Israel, and Prime Minister Najib Razak visited Gaza in 2013 at the invitation of Hamas, which governs the territory.
The intelligence officials said that Hamas, in recent years, had begun seeing the country as an ideal place to incubate its research ambitions.
On the day he was killed, Dr Fadi was supposed to travel to Istanbul to attend an academic conference. One Middle Eastern intelligence official, however, said that Hamas' efforts to cultivate its scientists living abroad were directed from Istanbul, and that Dr Fadi was scheduled to meet the head of the unit, Maher Salah, upon arrival in Turkey.
Western and Middle Eastern intelligence officials said that Dr Fadi may have been involved in negotiating North Korean arms deals through Malaysia.
Egypt recently seized a shipment of North Korean communications components used for guided munitions destined for Gaza, they said. One intelligence official said that Dr Fadi had helped mediate the deal.
Malaysian officials rejected that report. And this week, officials here would not comment on the claims that Dr Fadi had been researching or trying to buy weapons systems.