Leclerc was due to line up second on the grid behind Red Bull driver Max Verstappen, but the Monegasque spun off at Turn 6 (Ferradura) on the formation lap and hit the barriers.
This had been preceded by a small puff of smoke from the rear of his SF-23 before the back axle appeared to lock and snapped the car into a spin.
Speaking to Sky Sports F1, Leclerc reckoned an engine issue had triggered the spin as he also faced a subsequent hydraulic failure that ripped the steering wheel out of his hands.
He explained: “When I lost the steering wheel, I went straight basically because I had no hydraulics anymore.
“I don’t think it’s a hydraulic problem. I mean, I know what it is. I cannot go too much into detail.
“Then there was an engine thing that made me lock the rear wheels and then obviously I spun and hit the wall. I couldn’t do anything.”
Ferrari team-mate Carlos Sainz suffered a hydraulics failure during FP1 in the previous Mexico round, but Leclerc reckoned he had seen enough to suspect his issue was “completely different”.
After Sainz blamed a poor getaway on a clutch, Leclerc said: “I was happy with my car, we are changing the settings in between cars from weekend to weekend.
“I think he was unhappy with what they’ve done on their side of the garage but I’m on my side it was all good.”
Leclerc was initially able to drive out of the barrier but had sustained front wing damage. He then parked down an escape road to confirm his retirement.
The Brazilian GP was quickly red flagged after a sizeable Turn 1 shunt that wiped out Kevin Magnussen and Alex Albon.
Williams racer Albon had moved to the outside of Nico Hulkenberg off the line but the Haas clipped his rear tyre to send him spinning into Magnussen.
This ripped a tyre off the rim, which in turn clonked the rear wing of Daniel Ricciardo, as Magnussen spun into the back of Oscar Piastri.
Both Australians were able to take the race restart from the pitlane, a lap down, as the 25-minute stoppage for barrier repairs allowed the teams to complete car fixes.
