I went to the piratebay website today, but was getting a cloudflare error.
So, I did a search and found this thread on reddit, from November 2018....
https://www.reddit.com/r/newzealand/comments/a14def/isp_or_new_zealand_blocking_thepiratebayorg/
So it seems this has been happening since november 2018.
[edit] I also checked using a vpn and it works just fine, so I guess spark are now censoring knowing pirate websites.