"The ABC considered the episode unsuitable for broadcast in Australia and it had been restricted from being aired on the ABC's television networks," the broadcaster said in a response in August 2012.
"However, the episode was accidentally published online due to a technical problem. The ABC apologised to the complainant and advised that the episode was no longer available online."
The complaint was reported in recent days by the local media, though it was not clear why the incident only emerged this week.
In the banned episode, Daddy Pig is seen repeatedly picking up the spider by a string from its web. "Don't be scared, Mummy," says Peppa.
Deaths from spiders are exceedingly rare in Australia and the creatures are less life-threatening than sharks or bees. Antivenom for most of the more dangerous spiders has been available for decades.
But this summer Australia has reportedly seen an increase in spider-related injuries that has led to public warnings.
Last year, Sydney paramedics attended 319 spider-related incidents. There have already been 102 incidents recorded this year.
No deaths from funnel web spiders, the most dangerous in the country, have been recorded since an antivenom was introduced in 1981.
