Fragments of ceramic cups, a toothbrush and a shoe polish bottle dating back to the second half of the 19th century are among the historical items that contractors have found while working on Blenheim's new Alfred St parking building.

New Zealand Historic Places Trust central region general manager Ann Neill told The Marlborough Express the items were discovered in August, while workers from construction company Calder Stewart were completing foundation work.

When they were found, an archaeologist completed a report.

Ms Neill said the items were believed to come from Kirby Bros Coach Builders and Blacksmith, a former business on the site.

"The items are significant, as they provide information about the industrial and commercial activities of the 19th century.

"Archaeological remains can also provide a different view of history not often documented, such as the day-to-day activities undertaken on the site."

According to the Victoria University Cyclopedia of New Zealand, the business was run by two brothers, H and TA Kirby.

The business was established in 1885 by their father, JS Kirby, who was originally from London. When he retired in 1898, he left the business to his two London-born sons.

Documents say the business was "large and flourishing" in Marlborough during this time, after starting off very small.

The brothers and their workforce were kept busy with work from around the Marlborough district, building coaches and doing blacksmithing.

It is not known when the business closed.

Marlborough District Council executive project manager Jamie Lyall said the find had not caused any delays to the project, because the project team was able to work around the area.

"It's about being a prudent operator that if you find something, you need to assess if there's any value in it. There are no impacts on the project, delays, costs or anything like that."

The archaeologist who completed the report has kept the items, after direction by the council.

In three weeks' time, once the appeal process for the consent to continue working on the site has closed, an archaeologist will return to the site to monitor it for potential future finds.

This is a service provided free of charge by the trust.

The multi-level carpark is planned to be finished in April.

Do you know more about the Kirby Bros business on Alfred St? Call reporter Claire Connell on 035208933.