Sheik Shady Alsuleiman, who attended the Iftar Ramadan dinner hosted by Turnbull on Thursday night, previously said homosexuality was "spreading all these diseases" such as HIV and AIDS, The Australian reported.
"What's the most common disease these days?" the sheik said in a 2013 sermon. "HIV, AIDS, that's so common and there's no cure to it. And when did it exist? Just decades ago, and more diseases are coming."
Prime minister Malcolm Turnbull was quick to condemn the remarks when approached by The Australian.
"Views like this are wrong, unacceptable and I condemn them," he said.
At a press conference on Friday, Turnbull doubled down, saying "Homophobia is to be condemned anywhere".