Race control threw a red flag after just two laps at Suzuka on Sunday due to heavy rain that led to a couple of incidents on the opening lap, including a crash for Carlos Sainz exiting the hairpin.
Gasly was the last driver to return to the pit lane under the red flag, but was seen getting animated with team member in the garage after getting out of his car.
Onboard footage from the AlphaTauri car showed that Gasly passed a stationary tractor that was on the left-hand side of the track to recover Sainz's car. Although the race had been red flagged, Gasly was yet to return to the pits.
"What is this tractor on track?" Gasly shouted on team radio. "I passed next to it. This is unacceptable. Remember what has happened. Can't believe this."
Carlos Sainz said he "still doesn't know" why we "keep risking" having a tractor out on track, especially considering the race was red-flagged shortly after.
The Ferrari driver said: "I don’t know if people understand, but even behind the safety car, we are going at 100-150 kph, and still at those speeds, we don’t see nothing, even behind the safety car.
"If one driver decides to get a bit out of the racing line or has a small aquaplaning or has to change a switch on the steering wheel and gets a bit out of line, and hits a tractor, then it’s over, no?
"I still don’t know why in these conditions we keep risking having a tractor on-track, because it’s just worthless. If you’re going to red flag it anyway, why risk it?"
In a short statement relating to the incident, the FIA said: “In relation to the recovery of the incident on Lap 3, the Safety Car had been deployed and the race neutralised. Car 10, which had collected damage and pitted behind the Safety Car, was then driving at high speed to catch up to the field.
“As conditions were deteriorating, the Red Flag was shown before Car 10 passed the location of the incident where it had been damaged the previous lap.”
It comes eight years after Jules Bianchi suffered severe head injuries when he collided with a recovery vehicle in heavy rain at Suzuka. Bianchi died as a result of the injuries nine months later.
The incident led to widespread condemnation from many in the F1 community, including from GPDA director Alex Wurz, who said: "I think we need to discuss a tractor on-track. We can keep it short: this must NOT happen guys."
The FIA said the red flag was "due to worsening weather conditions and recovery operations required on-track."
The race was set to resume at 2:50pm local time in Japan (6:50am BST), but the restart has since been suspended.
