NSW man charged over child porn

A NSW man charged with several child pornography offences was allegedly caught in an online sting after making sexually explicit comments to undercover detectives.

Sex crimes squad officers last month began investigating the online activities of a man, 56, from Berowra in Sydney's north, and on Tuesday charged him with four counts of using a carriage service for child pornography.

"Using an assumed online identity, police spoke with the man on a number of occasions and will allege he made a number of sexually explicit comments," police said.

The man is due to front Parramatta Local Court on Wednesday.