A NSW man has been charged after allegedly performing unauthorised surgery to remove the left testicle of a financially desperate man.

Allan George Matthews, 56, from Glen Innes in the Northern Tablelands, was not a qualified nor registered doctor, police said.

However, earlier this year, he allegedly answered an online ad from 52-year-old Port Macquarie man David Hillier who was asking for assistance with a medical issue.

Fairfax Media understands Mr Hillier did not have the money to seek proper medical help and so was looking for alternative solutions.

It is not clear if he was aware that Mr Matthews was unqualified.