Blenheim police will lose 3.5 positions when a centralised file management centre is set up in Nelson within the next few months.

Typists, administration support staff and watch-house assistants made up of non-sworn police staff will be affected by the change.

Acting Marlborough area commander Inspector Richard Middleton said Marlborough had 7.5 full-time equivalent positions affected by the restructure, all of them in Blenheim.

Four of those positions would remain, he said.

"All staff have been fully informed of their status and their options."

Tasman district police spokeswoman Barbara Dunn said the centre should be running by September.

It will deal with court paperwork and other documents.

The move would free up frontline staff by reducing the load of administrative work they did, she said.

Although 3.5 positions would disappear, it was not known how many people would lose their job, Ms Dunn said.

"It's not that black and white. It depends on how other positions are carved up."

- © Fairfax NZ News