Deputy Prime Minister Grant Robertson is the latest MP to catch Covid-19.
Robertson is currently the highest ranked minister in New Zealand as Jacinda Ardern is in Europe.
He announced his positive Covid-19 test on Facebook and said he had "fairly mild" symptom and would remain acting prime minister.
"I guess it had to happen eventually! Fairly mild symptoms, but will try to do right thing and get some rest," Roberston said in the Facebook post.
"Still Acting PM while I am compos mentis (some would say that is questionable at best of times!) but grateful to colleagues for stepping in for House and meetings today."
Jacinda Ardern contracted Covid-19 in May, but had recovered in time for her visit to the United States and meeting with President Joe Biden.
Ardern is in Brussels as trade talks enter a critical stage, after making a speech at the NATO leaders' summit in Madrid in which she pushed New Zealand's "fiercely held" independent foreign policy while also condemning Russia's actions in Ukraine as an affront to the world.