Building on fire in Mt Wellington, Auckland

Firefighters are battling a large blaze at a building in the Auckland suburb of Mt Wellington. 

Footage obtained by Newshub shows clouds of thick, grey smoke billowing from MG Marketing, a fruit and vegetable wholesaler on Great South Rd in the lower Mt Wellington-Penrose area.

A crew and 11 appliances are working to suppress the "well involved" blaze, a spokesperson for Fire and Emergency told Newshub. The building's fire alarm activated automatically shortly after 9am, they said.

They confirmed no one is inside the warehouse.

A section of Great South Rd has been closed between Sylvia Park Rd and Vestey Dr as emergency services work to extinguish the fire, Auckland Transport (AT) said.

"Avoid this route or allow extra time for diversions."

In an update at 10:20am, AT confirmed Sylvia Park Rd is now closed to westbound traffic, while the eastbound lane remains open for southbound traffic detoured off Great South Rd.

In a statement, MG Marketing confirmed the fire ignited at its Auckland warehouse at roughly 8:50am.

"Staff were alerted by the fire alarm and everyone evacuated the building safely. There were no injuries," a spokesperson said.

"The fire service arrived shortly after the alarm was activated and are currently on-site working to put out the fire. The fire service are the only people able to access the site and a section of Great South Road has been closed to traffic."

The spokesperson said it is not yet known how the fire started and it is still too early to tell how much damage has been caused.

"Clearly this is a distressing event for our staff and our focus is on ensuring they are OK. We are also focused on working alongside our growers and our customers on plans to maintain our continuity of supply."