If the incident is in the delegate’s report and Celtic are found guilty, the suspended sentence of a one-match ban for their away fans will be automatically imposed.

There could also be further punishment, but that will be determined by Uefa’s control, ethics and disciplinary body, with an outcome unlikely until next week.

Celtic manager Brendan Rodgers was asked about the smoke bomb implication after the game but refused to be drawn.

The Scottish champions were already assured of a place in the play-off stage of the new Champions League format before their 4-2 defeat.

Celtic will now face either Real Madrid or Bayern Munich in a two-legged game to determine who progresses to the last 16.