According to Egypt's Youm7 newspaper, Hamas has refused to accept some 28 long-range missiles smuggled from Libya because it discovered that they were equipped with tracking devices that would allow Israel to know where they were.
The report says that members of the Al Qassam Brigades of Hamas inspected the missiles in the Sinai and discovered the tracking hardware within.
As a result, Hamas has ended its relationship with come of its arms smugglers.
Hamas suspects that Israel was behind these attempts.
It is certainly plausible that Israel would do this. It was widely reported that Israel had placed GPS tracking on some of the cars that were transferred into Gaza on the assumption that the first cars to be imported there would go right to major Hamas officials.