Officers were called at around 1.40am today (April 24) to reports of an altercation on Baffin Way.
Emergency services, including the London Ambulance Service and London Fire Brigade, also attended the scene.
A 26-year-old man sustained minor injuries but did not require hospital treatment.
The substance was later confirmed to be non-corrosive.
No arrests have been made, and police investigations are ongoing.
The Metropolitan Police is urging anyone who witnessed the incident or has relevant information to come forward.
Witnesses are asked to call 101 and quote reference number 493/24Apr.
A spokesperson for the Metropolitan Police said: “Police were called at 1.40am on Thursday, April 24 to reports of an altercation in Canary Wharf.
“Officers joined London Ambulance Service alongside London Fire Brigade at Baffin Way, E14, where a man had allegedly been assaulted, with an unknown substance thrown at him.
“The 26-year-old man received minor injuries in the incident.
“He did not require medical treatment.
“The substance was confirmed to be non-corrosive.
“No arrests have as yet been made.
“If you were a witness, please call police on 101 with reference 493/24Apr.”
