The 24-year-old 2-time world champion claims the comment came after the long jump events at the English Championships in Bedford on Sunday ... an interaction that left a bad taste in her mouth.

"I am always very grateful to the incredible volunteers who officiate at athletics events," Breen said on Twitter. "They do an amazing job and make it possible for us to compete."

"However, tonight I feel quite disappointed because just as I finished my long jump competition at the English Championships, one of the female officials felt it necessary to inform me that my sprint briefs were too short and inappropriate."

"I was left speechless."

Breen explained her shorts are made by Adidas and specifically designed for competition ... which she has worn for many years.

In fact, Breen -- who has cerebral palsy -- says she intends to wear the same shorts when competing for Britain at the Tokyo Paralympics in August.

"It made me question whether a male competitor would be similarly criticized," she added. "I hope no other female athletes had similar issues."

Breen notes she's all on board with having rules and regulations for what people wear during events, but says "women should not be made to feel self-conscious about what they are wearing when competing but should feel comfortable and at ease."

Breen told CNN that England Athletics has been supportive and in communication with her following the incident ... and she plans to file a complaint.