NSW cop assaulted after shop attack

A man has allegedly bashed a supermarket worker with a baseball bat before assaulting an officer at a police station south of Sydney.

It's alleged the 43-year-old man attacked the female staff member in a Shellharbour supermarket on Sunday evening before demanding money.

He was subsequently arrested and taken to Lake Illawara police station where he allegedly assaulted a police officer, who was treated in hospital for non-life threatening injuries.

The 57-year-old supermarket employee remains in intensive care in Wollongong Hospital with serious head injuries.

The man has been charged with aggravated assault and assaulting an officer and was refused bail to appear at Wollongong Local Court on Monday.