The style of burial could be indicative of iwi in the area, although the remains had not yet been officially linked to an iwi.
Jones said it was not uncommon to find burial sites in Horowhenua's sand dunes and remains had also been found at sites uncovered as part of the recent Kāpiti expressway.
A meeting would be held today with iwi, NZ Transport Agency and Goodmans, the contractor undertaking the Whirokino project.
The meeting would discuss what occured next, including whether the body would be preserved in-situ or disinterred for reburial elsewhere.
Goodmans project manager Guy Forrest said he didn't think the company had been involved with this kind of discovery before.
He said they were acutely aware of the cultural sensitivity involved and were being guided by archaeological authority protocols and iwi advice.
"Iwi have been particularly helpful on this project and we don't want to jeopardise that," he said.
Goodmans cheif executive Stan Goodman said all protocols were being followed, and he was unsure how long work would be halted in the affected area of the site.
"We're currently doing investigations to find out what's there, but it's too early to make too many comments," he said.
The remains were discovered during ground testing before scraping topsoil from a 10ha area to excavate sand for use in two Manawatū River bridge projects.
In all, 500,000 cubic metres was destined to be removed from the area before top soil would be restored over the site, Jones said.
He was working with fellow archeologist Hans-Dieter Bader during the testing, and with work now stopped in that area, further tests would now be carried out.
These included the creation of test pits as well as the use of a magnetometer, a device that detects changes in the magnetism of the ground, which could indicate the presence of objects.
■ NZTA has been approached for comment.
