Hard and bouncy yolks, like those associated with fake eggs made on the mainland, can also be found in real cooked eggs, Macau investigators say.
They made their announcement on Monday as the Hong Kong Centre for Food Safety was investigating complaints about suspected fake eggs.
Macau investigators said their initial findings suggested that there was no evidence of fake eggs in Macau markets, and that they had managed to make a hard and bouncy yolk out of a real egg by controlling its transport and storage conditions.
Ng Peng-in, an official with the Macau Civic and Municipal Affairs Bureau, said none of the samples that investigators analysed were fake.
He added that hard and bouncy yolks could develop in real eggs that had been shaken during transport and stored at very low temperatures.
Chinese University chemistry professor Tso Wung-wai said it can be quite difficult to distinguish between fake and real eggs, but shoppers could try gently nipping the shell.