Fire fighters are battling a large blaze at Shadowfax Winery in Werribee.

A dozen Country Fire Authority crews were called to the winery, located on K Road near the historic Werribee Mansion at about 7am this morning.

Broadsheet spoke to a CFA spokesperson who confirmed the fire started on the ground level in a kitchen. They also said that as of 7.40am the fire was under control, although at 8.30am 11 crews were still responding.

Motorists are being urged to avoid the K Road area due to high concentrations of smoke and because emergency services still fighting the fire.

It is not yet known what caused the fire, but it is not being treated as suspicious. The Princes Freeway remains open.