The discovery of a writing slate under the floorboards at one of New Zealand’s earliest schools has sparked a 190-year-old “missing person enquiry”.

The slate is one of several found during renovations at Kemp House, the country’s oldest surviving building, next to the Stone Store at Kerikeri Basin.

Two of the slates, which are thought to date back to the early 1830s, made headlines when discovered in 2000 because they are among the earliest examples of written te reo Māori.

One is signed “Na Rongo Hongi a(ged) 16″ by the daughter of Ngāpuhi chief Hongi Hika, who later married Hone Heke; while the other is inscribed with an early waiata whakautu [song of reply].

Now, however, it’s another slate’s turn for a share of the limelight.

Heritage New Zealand Pouhere Taonga collections adviser Belinda Maingay said the third slate had been somewhat overshadowed by the huge significance of the other two.

“Although it doesn’t have nearly the same amount of provenance or information recorded on it, our third slate is still important. It includes one written element that we’d really like to learn more about,” she said.

That element was the signature, “Na Kapu”, etched on the bottom right corner.

Maingay said she was keen to hear from anyone with information from whakapapa or other sources that could shed light on Kapu’s identity.

“We know that the small missionary school at the back of Kemp House was operated by Charlotte Kemp and Martha Clarke, and that the girls who attended classes tended to be high-born daughters of rangatira,” she said.

“We’d be very interested to find out more about Kapu’s identity and any information about her life after she left the school.”

Anyone with information could email bmaingay@heritage.org.nz.

The other two slates were added to the UNESCO Memory of the World Aotearoa New Zealand Register in 2018. The register is a list of the world’s most important written records.