Hamas has arrested the suspected murderer of one of its key military commanders in the Gaza Strip, the Islamist movement's leader said Thursday, while maintaining Israel was responsible for the March assassination.

"We announce that the killer and criminal that carried out the orders of the officers of the Zionist security services is in the hands of the (Hamas) security services," Ismail Haniya told journalists in the Gaza Strip. "He has confessed to the crime."

No details were provided on the suspect's identity, though Hamas has previously suggested Palestinian collaborators worked with Israel on the assassination. (AFP)