The Warehouse says the Grocery Commissioner needs to chop-chop on reform.

The retailer claimed an investigation into Sanitarium briefly stopping its supply of Weet-Bix isn't happening quick enough.

Sanitarium kept up supply to supermarkets.

Warehouse Chief Product Officer Tania Benyon says combined with online grocery startup Supie failing - it's reason for prompt action from the Commissioner.

"He should really use the powers that he has to stop that. We want a fair and level playing field, and he is the person able to do that."

LISTEN ABOVE

• Weet-Bixgate: Sanitarium backs down after furore with The Warehouse
• Supie failure shows need to 'break up' Woolworths, Foodstuffs dominance- critic
• Supie start-up struggled from day one- analyst
• Jack Tame: Our new Grocery Commissioner needs to address the brutal, entrenched reality of the sector