Transport Minister Shane Ross has asked the Irish Aviation Authority (IAA) to ban drones above a site in Dublin where gardaí are searching for Trevor Deely.
A search has been continuing at a site in Chapelizod in the west of the city.
The then 22-year-old disappeared after attending his office Christmas party in Dublin in 2000.
Gardaí have designated the site as a crime scene after receiving new information.
The IAA say they received the request for temporary restrictions due to the security operation.
The request was made by the Department of Justice and approved by Minister Ross.
The restrictions are in place from August 16th to August 30th.
The IAA has issued a direction to establish an area of temporary restricted airspace (TRA).
It includes a ban on flying aircraft, including small unmanned aircraft, in airspace over Chapelizod.