well yes, against the law
as that was what I was accused of
( surprisingly I was able to show I had taken NO photos that you cd complain about - to my accuser's Great Discomfort. Light, I showed, does not go around corners or vault 6' fences. Oh and I said I cdnt fly or hover either)
Clearly we didnt get to charges altho I thought making indecent photgraphs was the obvious one. - er that I cdnt be accused of.
Dr Fielden did this, and was convicted of voyeurism
https://www.bbc.co.uk/news/uk-england-beds-bucks-herts-48501791
so yeah it is against the law.
But remember you do sort of have to prove your case. "He did you know. I am SURE of it" isnt really good enough. "He took them and then he must have deleted them" isnt really a goer either.
a visit to the police is in order. ( so long as it wasnt a box brownie in 1957 and so on).
There seems to be some idea on this site that you can take photos of naked children and say " I can do this you know".
You cant. If the facts are as stated: police