A sperm donor, who claims to have fathered at least 100 children, has revealed he is only tested for sexually transmitted diseases "annually".
The US man, who operates under the moniker "Joe Donor", hit headlines earlier this week when he appeared on TV, discussing his unusual career.
Now Joe may ruffled some more feathers after telling news.com.au his last sexual health test was approximately six months ago — something experts say isn't good enough.
In a statement, sent to news.com.au, Joe Donor said his clients shouldn't worry about contracting sexually transmitted diseases from him, as he has undergone some testing in the past.
"I do testing at least annually," he told news.com.au. "The last time was in September, as recommended by the Center for Disease Control in Atlanta, Georgia."
The shock confession has prompted an urgent warning from health experts to any of Joe Donor's clients to undergo immediate sexual health testing.
Fertility specialist and Gynaecologist, Sonya Jessup told news.com.au someone in Joe's line of work should be tested for STDs "after every patient he sleeps with".
"If he has had unprotected sex with someone, he should undergo a full STD screening immediately afterwards," Dr Jessup said.
"Also, he should wait at least three months before having unprotected sex again. If he has contracted HIV, it takes at least 12 weeks to show up on any test."
Dr Jessup said Joe Donor's sparse history of sexual health checks should be seen as a major red flag.
"Women who are choosing to travel down this path with Joe Donor are putting themselves, and their children, at an extraordinary risk," Dr Jessup said.
"There is no knowing how many children have been born to this man, or what genetic diseases he might be passing on."
The private sperm donor, who was interviewed for 60 Minutes this week, is currently touring Australia with plans to impregnate 15 women.
He refuted reports that suggest he charges fees for a vial of his sperm.
Instead, he referred to these costs as "expenses" that aren't applied if clients agree to have sex with him.
"I pass on expenses such as a hotel," Joe said. "But if a woman is doing natural insemination, in her house for example, well, a hotel might not be necessary and there is no expense to pass on."
Dr Jessup said the service Joe offers isn't worth the time or risk to a woman's health.
"It's a very similar situation to going down to the pub, getting a drink and picking someone up," Dr Jessup said.
"Also, you don't know whether that stranger is carrying an STD, so it doesn't seem a very sensible way to go about things".
She said the most concerning thing was that there is "no way of finding him because he only goes by this made up name".
Joe Donor also challenged opinions about the women he impregnates, after reporter Liz Hayes suggested they were "irresponsible" to use his services.
"Some (women) have unstructured lives but my experience has been that the baby will give their lives structure," Joe said.
He also defended himself when he said "even monkeys can raised babies".
"I was referring to the instinctive ability of all primates to raise their young," he said.
According to Dr Jessup, for about $3500, a woman can conceive in a safe space, with an expert support system behind her, rather than a dingy motel room.
"Using a sperm bank or IVF service may cost slightly more in Australia but it's sterile, in a clean environment and at the correct time in your cycle," she said.
"There are so many reasons why there are better options available to women than what Joe Donor is offering."