It issued red notices, its highest-level alert, for a 16-strong team accused of “closely watching, following and reporting” the movements of Mahmoud al-Mabhouh before his killing.
Interpol said it had issued the alerts at the request of authorities in Dubai, in the United Arab Emirates.
It already has issued red notices for 11 other people suspected in the January killing.
The methodical stalking and killing of al-Mabhouh in a luxury hotel room has been widely blamed on Israel’s Mossad spy agency. Israel has neither confirmed nor denied involvement.