The 89-year-old, most famous for his alter egos, Dame Edna Everage and Sir Les Patterson, had been hospitalised after a fall at his home broke his hip.
However, days after his release, he was readmitted after complications from a hip replacement.
Sunrise Entertainment Editor Peter Ford, who broke the news on Wednesday morning, said Humphries was still determined to be back on stage by the end of the year.
“Barry won’t give up easily. Whether that’s a realistic goal, I don’t know … I am told that Barry’s health has worsened in the last week,” said Ford.
Speaking to the Sydney Morning Herald last month, Humphries said he had been in “agony” since the initial incident occurred.
“It was the most ridiculous thing, like all domestic incidents are. I was reaching for a book, my foot got caught on a rug or something, and down I went,” Humphries said.
Ford told Sunrise viewers Humphries’ family had “serious concerns” about the entertainer’s health.
“Things are tough. But Barry has a fighting spirit, and he won’t give up easily. [But] There are very serious concerns about what happens next … it is a very tough time at the moment,” he said.