Is it illegal to transfer the monitored property to the owner privately?

It depends on what the situation is, what the purpose of the property is, what monitoring is taken and who to show it to.

Generally speaking, the monitoring of property is not allowed to the outside world, and private access and copying are prohibited, only the public security organs can. However, there are also provincial and municipal regulations that when the owner's vital interests are damaged, he can consult the video materials related to his own damage, but he can only watch them and cannot copy them. If not, the property is suspected of infringing on the privacy rights of others.