EMB-145 Captain reported they were informed that ground personnel smoke observed emanating from the right wheel during taxi. Flight crew returned to gate and passengers deplaned.

Narrative

While taxing to Runway XX after completing de-icing for the flight to ZZZ [Airport]; ZZZZ Tower informed the crew that personnel in a ZZZZ Airport vehicle reported seeing what appeared to be smoke emanating from the right wheel assemble of the aircraft. The crew observed no abnormal indications with the brake temperature indicators and did not notice any braking or steering problems with the aircraft. Since the flight was in sequence to takeoff; ZZZZ Tower instructed the flight to taxi onto Runway XX and hold to facilitate permitting the flight to taxi out of the takeoff taxi flow. While holding on the runway; the Tower reported the Airport personnel did not observe any smoke emanating from the right wheel assembly while the aircraft was stopped. After clearing the runway; Tower reported the Airport personnel once again observed what appeared to be smoke emanating from the right wheel assembly while the aircraft was moving and that it appeared the right outboard wheel was not rotating. The flight returned to the gate and deplaned the passengers. Again; during the taxi back to the gate; the crew did not observe any unusual indications on the flight deck and did not experience any problems with steering or braking the aircraft.Cause: Possible failed brake assembly on right main landing gear.Suggestions: Continue using all available resources inside and outside of the aircraft to evaluate abnormal situations.