When Israel Adesanya defended his UFC middleweight championship at UFC 263 on Sunday, he dedicated the win to late City Kickboxing teammate Fau Vake, who died from injuries sustained after an alleged attack from behind during a night out in Auckland.

Outside of the octagon, Adesanya used his platform to call upon Prime Minister Jacinda Ardern to implement harsher penalties for coward punchers, despite the government having turned down a bill to do so in June last year.

The defeated bill was proposed in 2018 to create a new offence that would allow for a specific "king-hit" or "coward's punch" offence. The maximum penalty would be 20 years imprisonment; a similar punishment to the one states across Australia have been adopting for the same offence since New South Wales introduced it in 2014.

One man has been charged with manslaughter, while three others face assault charges in relation to Vake's death. All four were remanded on bail without entering pleas last week, and will next appear in the High Court in Auckland on June 23.

"Australia was ahead. They created a really harsh penalty for people who blind shot people, and you'd expect New Zealand to do the same thing," Adesanya told media in Arizona on Sunday.

"For what reason would you want to pass on a bill like that? If someone who walks up to someone who is doing nothing, be it an old man or old lady or whatever, and blind shots them from the back, give them 20 years – standard.

"I don't want to get angry, I don't want to get political, but I expect better from the government of New Zealand. But I'm not a politician; don't f***ing listen to me...but I know right from wrong, and that was f***ing wrong what they did to my boy. It was wrong, and they know that too.

"Jacinda, I don't know who else is in your cabinet, but you know it was wrong, you know exactly what to do. I don't know what puppet master is pulling the strings, but you're the leader of the country. You handled to mosque shootings like a f***ing champ, can you please do the same with this s*** too?"

Both Adesanya and teammate Brad Riddell dedicated their wins at UFC 263 to Vake, with Riddell using Vake's walkout song as his own ahead of his Fight of the Night bonus-winning bout against Drew Dober.

Vake, who was just 25 years old, was a promising mixed martial artist and one of the country's top prospects – often troubling New Zealand's UFC stars during sparring sessions. His death occurred during the back end of Adesanya and Riddell's fight camp, and is something the pair said they haven't fully allowed themselves to feel yet.

"He gave me quite a lot of hidings on the regular with his hands," Riddell said of Vake. "Everyone knows this world isn't fair, and he'll never get to make that walk to the UFC, even though he would have one day.

"I've bottled it up over the past couple of weeks. I kept it inside because I knew the best way to pay tribute to Fau was by winning, so it was easier for me to keep my emotions contained until afterwards.

"[Now] I've got two weeks in quarantine to sit in a room and think things over. I'm fortunate to be with a good group of people in that quarantine, and they're the people I want to talk with about it."