The police chief said investigators narrowed down the type of motorcycle used by the suspects to either a BMW GS or a Kawasaki Versys.
"We say to them, we will not let them sow our lands and enjoy them".
Two men on a motorcycle fired at least 14 shots at Mr Fadi al-Batsh, an engineering lecturer, at 6am on Saturday, killing him instantly.
But if, as many suspect, the alleged killers are agents with Israel's Mossad intelligence service they may never be found. Police said security video showed that the suspects had waited for him for nearly 20 minutes.
The family said the body was expected to cross from Israel late Wednesday, with the funeral to be held on Thursday.
In another mystery killing of a foreigner in Kuala Lumpur, two women, an Indonesian and a Vietnamese, are on trial for murdering the half-brother of North Korean leader Kim Jong Un by smearing his face with VX, a banned chemical weapon, at the airport in February previous year.
Anwar al-Agha said Tuesday that Egypt agreed to allow the body to be returned through its border with Gaza.
Palestinian group Hamas on Wednesday denied reports about negotiations for a prisoner swap deal with Israel.
A string of Israeli officials have neither confirmed nor denied whether Israel had a hand in the killing. Several Israeli Cabinet ministers welcomed the killing, regardless of who was responsible.
The head of the political bureau of the Palestinian Hamas resistance movement, Ismail Haniyeh, has vowed that his group will leave no stone unturned to find out the circumstances behind the assassination of a Palestinian lecturer and electrical engineer in Malaysia.
A spokesman for the Israeli government didn't comment on the killing, however on Sunday Defense Minister Avigdor Liberman said on Israel Radio that Batsh was "no saint" and suggested that his killing was the result of "a settling of scores among terrorist organizations".
Malaysian forensic police collect evidence in the area, where a Palestinian scientist was assassinated in Kuala Lumpur on April 21, 2018.