The disclosure confirms gaps in the child protection measures of some of the world's biggest tech firms, building public pressure on them to do more, according to the commissioner.
Meta Platforms Inc, (META.O) which owns Facebook, Instagram and WhatsApp, and Snapchat owner Snap Inc (SNAP.N) also got demands for information.
The responses overall were "alarming" and raised concerns of "clearly inadequate and inconsistent use of widely available technology to detect child abuse material and grooming", commissioner Julie Inman Grant said in a statement.
Microsoft and Apple "do not even attempt to proactively detect previously confirmed child abuse material" on their storage services, although a Microsoft-developed detection product is used by law enforcement agencies.
An Apple announcement a week ago that it would stop scanning iCloud accounts for child abuse, following pressure from privacy advocates, was "a major step backwards from their responsibilities to help keep children safe" Inman Grant said.