Who killed Ashraf Marwan, described as the 20th century’s greatest spy?

I always thought there was something about the death and investigation that didn't fit well. That area is covered in London by CCTV etc, the fact that the investigation didn't really go anywhere is strange.

On the face of it, I and many other Bregman students thought Israel was the most likely immediate candidate for the killing - but doing it in London and in such a high-profile way didn't really seem like their modus operandi (plus the description of "Middle Eastern looking men" on the balcony wouldn't really fit with a "kidon" team sent to kill him). Also his actions had been known for years by Israel, so why do it now?

Marwan was clearly playing so many sides and involved with so much intrique that there were many who might have wanted him dead.

Also, i'm sure there are probably many other people who might be deemed worthy of a the "20th Century's greatest spy"

EDIT: Oh i am foolish, I know this guy, have read a book