Investigator Tarek Bitar did not mention which countries could have information from before, during and after the detonation that caused the catastrophe.
The ignition of 3,350 tons of ammonium nitrate improperly stored in a warehouse at the port terminal caused a tragedy that left some 200 deaths, 6,500 injured and destroyed the homes of 300,000.
Days after the explosion, President Michel Aoun revealed that he asked France for satellite images to see if they showed planes or missiles.
The authorities never ruled out an attack although so far there is no evidence to suggest it.
Youssef Diab, a Lebanese journalist close to the investigation, said that the countries likely to provide the information are the United Arab Emirates, France, the United States, China, Japan, Canada and Turkey.
The idea is to find out if there were any aircraft or drone flights over the port or if it was attacked.
Eight months after the explosion, it is still not clear what caused a fire in a nearby warehouse due to which the ammonium nitrate exploded.