"When they opened the baggage area, maggots spilled out," Willy Silberstein, a 60-year-old journalist on the flight, told newspaper Aftonbladet.
Silberstein was on a flight to Stockholm's Bromma airport on Sunday.
The passengers were told that their baggage would be flown back to Brussels, to be either sanitized or destroyed.
"In these times of ebola, it's understandable that they have to be careful," Silberstein said. "But it's certainly unusual."
The operator of the flight, Brussels Airlines, reported that the infestation was thanks to one passenger who had packed expired food.
"I can confirm that we have had sanitation problems with a passenger's baggage, which apparently contained food which was expired and rotten," spokesman Geert Sciot said. "It was transfer baggage from another continent."
The airline said on Monday that the infested bag had been destroyed, and the remaining bags had been sanitized in Brussels. The baggage will be flown back to Stockholm on Monday evening.