Sydney man kidnapped over business deals

A man has been kidnapped, tied to a chair and threatened over business deals in Sydney's southwest.

The 50-year-old man was hit over the head from behind as he completed building tasks at a house in Sydney's west on Monday morning, police allege.

He lost consciousness and was tied to a chair when he awoke.

The man's kidnappers allegedly threatened him over business dealings before releasing him a short time later.

Police raided the house on Wednesday and seized several items including drugs.

Three men at the scene were arrested and charged with kidnapping and assault charges.

One of the men was also charged with demanding money with menace and supplying prohibited drugs.

They were all refused bail to appear at Liverpool Court on Thursday.