The rugby player mixed the two pints of gin with teabags and said to the camera: "This is how you drink."
Bradley, 20, then filmed himself downing the concoction in a matter of minutes, but complained of feeling ill shortly after.
He commented underneath his Neknomination video: "Haha I feel sick, belly is hurting."
A friend responded: "someone died from doing that! don't ever do it again… not be able to show people who's boss if ya dead"
Four days later Bradley died, the Mirror reported.
A spokesperson for the Kaleidoscope alcohol awareness charity explained that two pints of gin was a “massive amount” to drink, effectively “playing Russian roulette”.
He said: “Government guidelines for alcohol consumption say 21 units a week for the average adult male.
“Here people are having more than that in one or two minutes. They are overloading their bodies.”
The day the young man's body was found at home in Nottingham, his stepmother reportedly posted a link on social media to another Neknomination-related death and wrote: "You all need to stop now."
Police have said they are aware of the Neknomination video but have added that an initial post-mortem has prove inconclusive.
Officers are also investigating the death of Stephen Brooks, 29, who collapsed after drinking three quarters of a litre of vodka in under a minute.
They are also planning to speak to the person who “Neknominated” 20-year-old Isaac Richardson, who died after taking part in the drinking challenge.
He drank a cocktail of wine, whisky, vodka and lager and later collapsed; hospital staff were unable to resuscitate him.