3:23 PM PT -- Sources tell us the Kings are aware of the allegations and looking into the situation.
Edmonton Oilers star Evander Kane says a number of Kings supporters turned a dream trip into a complete nightmare for a young fan last week ... accusing L.A. backers of harassing and spitting on her jersey during a Stanley Cup playoff game.
Evander shared the allegations via social media ... saying 10-year-old Cecily Eklund -- who is battling cancer -- was singled out for wearing a Kane jersey during Game 3 of the Kings vs. Oilers series at Crypto.com Arena on Friday.
"I'm disgusted and appalled at what happened to this amazing little girl in the stands and in a women's restroom where she was harassed for wearing her jersey and was spit on by a LA fan for doing so," Kane said.
"This type of behavior is gross and unacceptable."
Kane went on to call the alleged conduct "pathetic" -- especially considering Cecily is a young warrior going through challenging times.
What makes things even worse -- Kane later shared a follow-up from someone DEFENDING Kings fans over the whole thing ... stating the awful human beings behind the alleged hateful actions had no other choice because he's "such a f***in scum bag."
"You make us spit on kids for being a dirty mother f***er," the user added.
Evander and Cecily have been tight for some time now -- the two met through the Ben Stelter Fund, which helps young kids battling illness have once-in-a-lifetime experiences.
The alleged hate isn't affecting Cecily's pride, though -- she says she is still planning to go to Tuesday night's game back on home turf.