NSW man charged with child exploitation

Detectives have swooped at a Sydney pedestrian mall to arrest a man accused of child pornography offences and allegedly found a large knife in his backpack.

Officers from the Sex Crimes Squad arrested the 31-year-old in Parramatta's Church Street on Thursday morning, and seized a mobile phone and the knife.

Detectives began engaging with the NSW Hunter region man online in July, and will allege the man believed he was speaking to a 14-year-old girl and had arranged to meet in person.

He was charged with online child exploitation offences and refused bail. He is expected to face Parramatta Local Court later on Thursday.