A woman has been charged over the death of a critically injured man found dumped outside a hospital on the NSW north coast.

A 50-year-old woman was arrested at Forster police station about 11.40am on Tuesday.

She is the third person to be charged since the 38-year-old died after he was found with life-threatening injuries outside a hospital in Taree on the morning of April 23.

Initial inquiries suggested the man was injured at an address on Heath Ave in Tuncurry before being driven to hospital by a family member.

Matthew Ronald Bennis, 31, was charged with his murder and Kaia Lynn Ridgeway, 25, was accused of concealing a serious offence.

The pair were arrested at a motor inn in Forster earlier this month and remain before the courts.

The 50-year-old was charged with being an accessory after the fact to murder and accessory after the fact to malicious wounding, NSW Police said in a statement on Thursday.

The woman appeared before Taree Local Court on Wednesday and was refused bail to appear before the same court on July 24.