New Delhi, Aug. 27 -- Flipkart is under preliminary investigation over allegations that the Walmart-owned online marketplace altered its billing structure in a way that could reduce its goods and services tax liability, two tax investigators said.

Flipkart allegedly rejigged its billing model by recasting marketplace fees collected from its vendors as transport charges to claim lower GST rates applicable to goods transport agencies by shifting revenue to a category meant for small road transporters.

The Directorate General of Goods and Services Tax Intelligence (DGGI) is currently conducting due diligence into complaints against Flipkart, officials said.

"We will send a show-cause notice for prosecution once we have accumulated full pr...