The shirts, which are on a stall close to shops selling stuffed koalas and boomerangs, have been branded ignorant by a multicultural group.
One shirt, featuring the Australian map and flag, has the phrase, "This is Australia we eat meat, we drink beer and we speak f-----' English!'
Another sports the flag with the phrase, "Support it or f--- off!"
Andrew Jakubowicz, chair of the Institute for Cultural Diversity, said: "If somebody is so unsure about their identity that they need to use that kind of (phrase), it says more about them than it does about anyone else.
"It might take a while for some Australians to speak English, but those who use it the best don't need to use those kinds of words to make a point."
The discovery of the provocative shirts comes after the Federation of the Ethnic Communities Councils of Australia met sporting, religious and ethnic groups around the country last month to tackle racism nationwide.
Queen Victoria Market spokeswoman Misti Dullard said the market was "investigating the appropriateness" of the T-shirts and other items sold by stall operators.
"We have noticed that recently there has been an increase in (those) types of T-shirts," Ms Dullard said.
"Assuming the trader in question is permitted to sell T-shirts under our agreement with them and those T-shirts are legally and generally available then there is little that Queen Victoria Market Pty Ltd can do."
She said the market was widely recognised as one of the multicultural hubs of the city. The Australian manufacturer of one of the shirts, Samsousan Designs, also sells drug and sex-themed shirts online.
"The person wearing this T-shirt is a police officer lie flat on your back and do everything the nice police officer tells you to do," one shirt on the Samsousan website reads.
Sunday Herald Sun
