New Zealand's Labour party has new leaders less than two months from the general election.

Last week's polls showed the party at a record low twenty four percent support, prompting leader Andrew Little to offer his resignation.

This morning in Wellington his offer was accepted and Jacinda Ardern was elected unopposed as the party's new leader.

Ardern's second in charge is Northland's Kelvin Davis, who was also elected unopposed at the party's caucus meeting.

Ice was a serious issue for Otago motorists over the weekend.

Sunday morning saw heavy frosts over much of the region, but luckily most roads were dry with black ice absent.

With clear skies forecast for the much of the week, motorists on inland roads should look out for icy conditions.

As always, winter driving conditions means care needs to be taken on roads.

This is especially true in places that can remain frosty all day, such shaded areas and approaches to bridges.

The Ministry for Primary Industries is working with a South Canterbury dairy farmer to contain a cattle disease which has been detected for the first time in New Zealand.

Mycoplasma bovis, which has been commonly found in cattle globally, including Australia, doesn't infect humans and presents no food safety risk.

Ministry response director Geoff Gwyn says there is no concern about consuming milk and milk products.

However, the bacterial disease can have serious effects on cattle, including udder infection, abortion, pneumonia and arthritis.

Southern and Waikato Police district investigators have seized approximately 130 grams of methamphetamine, worth $130,000, and an estimated $80,000 in cash.

Officers searched addresses in rural Otago and Hamilton yesterday.

They seized cannabis plants, dried cannabis head, and other items indicative of drug dealing.

A 48-year-old man was arrested and charged with conspiracy to supply methamphetamine.

He was due to appear in the Dunedin District court today.