Family and friends have expressed their grief after young mother Lynace Parakuka was found dead at a Rotorua school.

Rotorua police have launched a homicide investigation after they found the 22-year-old's body on the grounds of St Michael's School in Lisa Crescent, around midnight on Friday.

"So sad, rest in peace. Taken so young and early," one relative said in a social media post.

"I love you to infinity and beyond," a friend posted.

St Michael's Catholic School principal Kristina Crouch said the board of trustees were both "shocked and saddened" that a suspected homicide had occurred on the school grounds.

"Our school is a close and tight-knit Christian community, and we know that all of our staff, students and their families will be as shocked and upset about this as we are.

"Obviously, our first concern is the well-being of our students and their families. We would also like to extend our deepest sympathies to the families involved. We encourage our faith community to offer their prayers to those who grieve."

The school was working alongside police and would be sharing more information regarding school on Monday.

Detective Inspector Mark Loper said Rotorua police held a briefing on the investigation just before midday on Saturday.

"A scene examination is under way with scientists from ESR, and we are trying to speak to as many people as possible," he said.

When asked how long the woman had been dead before emergency services arrived at the scene, Loper said "I can't tell you that, that's part of the investigation."

Lydia Naera, who lives opposite the school gates on Clayton Rd, said she first noticed emergency services at the school at about 11.45pm on Friday.

She said she was driving home from the pokies when "zoom, an ambulance went straight past me".

"All the cop cars amalgamated out here all the cop cars and I'm like something bad's happening."

Police would like to hear from anyone else who may have heard or seen anything in the area - for example, yelling or arguing – between 8pm and 11.40pm.

If you can help, please call Rotorua police on (07) 349 9400. Information can also be provided anonymously via Crimestoppers on 0800 555 111.