Police said the two-car crash happened at 3.53pm on Saturday.
The highway at Mangaiti was closed for more than four hours while the Serious Crash Unit investigated.
A Hato Hone St John spokesperson said two people from the other car were airlifted to Waikato Hospital with serious injuries.
The local theatre community has paid tribute to Swallow, who was involved in several plays.
Te Aroha resident and friend Les Munro said he had directed Swallow as part of the Te Aroha Dramatic Society.
“He was a lovely guy who connected very well with people and was involved in everything he could.”
Te Aroha Dramatic Society vice president John Watson told the Herald that Swallow had been involved with the society for quite a few years.
In a post on its Facebook page, Te Aroha Little Theatre said his last role on stage with them was in the play Remain in Light.
A person who performed alongside Swallow said he had been great to have on stage.
“I will remember him as the Italian Captain in Allo Allo. So funny, so great to work with.”
Another remembered him as “brilliant” in the role.
Childhood friend James Brodie wrote he had known Swallow since they appeared in a production when they were at primary school.
“This one hurts. Peter and I have known each other since we were in single digits on the stage of Future Te Aroha and we’ve been very solid friends ever since.
“Fly high Peter. The spotlight’s shining on you. Step right up and let the music play. Rest in Paradise.”
