Zola died on 29 September 1902 of carbon monoxide poisoning from a blocked chimney flue in his Paris bedroom. Decades later a Paris roofer was reported, in an account relayed after his own death, to have claimed he had deliberately blocked the flue at the request of Zola's anti-Dreyfusard enemies; the claim was never made under oath, never corroborated by a second source, and no criminal investigation at the time or since has reached a conclusion either way.
What would resolve this A corroborating primary document (police record, a contemporaneous confession, or forensic reexamination of the original 1902 chimney and flue) that the 1902 investigation itself did not produce and that no later inquiry has located.
OpenHistory; forensic historyEmile Zola (Britannica)