"As more companies move towards encrypted messaging services and deploy features like livestreaming, the fear is that this horrific material will spread unchecked on these platforms," she added.
A spokeperson for Microsoft, which owns video calling service Skype, said the company had received the letter and planned to respond within 28 days.
A spokesperson for Meta, which also owns messaging service WhatsApp, said the company was still reviewing the letter but continued to "proactively engage with the eSafety Commissioner on these important issues".
Apple, which owns video messaging service FaceTime, messaging service iMessage and photo storing service iCloud, did not immediately respond to an email seeking comment.
The eSafety Commissioner referred to figures provided by the US National Center for Missing & Exploited Children, which said this year it had received 29.1 million reports of child abuse material from internet companies, of which just 160 were from Apple while 22 million were from Facebook.