McGregor has fuelled much of the pre-fight hype with his standard over the top antics, and the angst has only risen since Aldo pulled out of their scheduled showdown at UFC 189 in July.
More: UFC star admits drug addiction
Aldo was forced out with a rib injury and was replaced by Chad Mendes, which only fuelled McGregor’s fire.
Now, Aldo has taken to the press in his native Brazil to question whether the Irishman is being adequately drug tested.
“He’s not being tested in Ireland. I don’t even know if there’s a commission there,” Aldo told Combate.
“This commission had to be from Vegas or anywhere.
“We said that, like he said it a lot, we wanted to be tested every week at the same time – me and him. But it didn’t happen.
“I’m being tested a lot – they come here to the gym.”
Ireland doesn’t have a governing body for mixed marital arts, but USADA does all the drug testing of UFC fighters the world over.
USADA records show Aldo and McGregor have both been tested four times over the past several months.