Thanks very much for your detailed response.
When the website was hacked they created the hacked pages and when you searched in Google you would go to an actual page. Once we shut the attack down, the links went back to our website.
I thought I had it under control. Listed in search console not to to index links and was going to place redirects on. But in the last few days another 5 pages of the bogus links have been created. Just checked again and more bogus links are being created. Therefore it could be an endless job, if they are going to be added to.
Correct client is a Air Conditioning service business. When you go to site:mechfieldfm.com.au the first couple of pages are actually from client website.
I will look at locking down the HTTP>HTTPS redirect.