The pair were battling for sixth place in the closing stages of the Albert Park race, with Russell closing in on Alonso, having pitted later and with the benefit of fresher tyres.
Approaching Turn 6, Russell appeared to suddenly gain on the Aston Martin ahead, which destabilised his Mercedes and sent him over the gravel and into a heavy hit with the wall.
Russell has confirmed he is OK having been checked over the by FIA medical team and after the race the incident was placed under investigation by the stewards.
Speaking to Sky Sports F1, Russell held back on accusing Alonso of wrongdoing but felt the scenario was "bizarre".
"My take is that I have gone off, and that is on me, but I was half a second behind Fernando 100m before the corner and then suddenly he came towards me extremely quick and I was right in his gearbox," Russell said.
"I don't know if he has got a problem or not. We are off to see the stewards so that is a bit bizarre in a circumstance like this. I've got nothing more to say right now, I need to see everything, I am disappointed to end the race like that."
When asked directly if he felt Alonso brake-tested him, Russell replied: "It is clear that he braked 100m before the corner and then went back on the throttle again and took the corner normally.
"We've already seen the data of that so I am not going to accuse him of anything until we've seen further.
"But I was right behind him for many, many laps and I was half a second behind him approaching the corner and then suddenly he slowed up dramatically and got back on the power.
"I wasn't expecting it, it caught me by surprise. That part is on me, but it is interesting that we've been called to the stewards so I am intrigued to see what they have to say."
Alonso has also responded to the incident before the FIA stewards hearing and explained he was managing a battery problem.
"I was focusing in front of me and not behind. I had some issues for the last 15 laps or something on the battery, on the deployment," Alonso told Sky Sports F1. "I was struggling a little bit at the end of the race, but, I cannot focus on the cars behind. But he's okay, apparently. I saw the car and I was very worried.
"I knew that he was coming and he was on the DRS distance for already five or six laps. So yeah, it was very close. I was just doing qualifying laps and trying to maximise the pace. It was not an easy race, not an easy weekend in general in terms of pace.
"Today we got lucky with the strategy and when Lewis was off and that virtual safety car but we cannot hide that the pace was difficult the whole weekend."
Both drivers have been summoned to the stewards at 5:20pm local time in Albert Park.
