India’s leading e-commerce platforms, Amazon and Walmart-owned Flipkart, have come under scrutiny for breaching the country's quality control regulations by stocking uncertified products, according to India’s top government-run certification body.

On Wednesday, the Bureau of Indian Standards (BIS) conducted raids on warehouses operated by both companies in Tiruvallur district, Tamil Nadu. The government reported that the firms were found storing, selling, and displaying products that lacked the mandatory BIS certification mark.

Neither Amazon nor Flipkart immediately responded to requests for comment.

The raids add to the ongoing challenges faced by the retail giants, which dominate India's e-commerce sector—estimated at $57 billion-$60 billion in 2023 and projected to exceed $160 billion by 2028, according to Bain & Company.

At an Amazon warehouse, authorities seized 3,376 uncertified items, including flasks, insulated food containers, toys, and ceiling fans. Meanwhile, at a Flipkart facility, officials confiscated diapers, casseroles, and stainless steel water bottles.

This latest regulatory setback follows an antitrust probe last September, which found that both firms violated competition laws by favoring select sellers on their platforms.

In November, investigators raided multiple Amazon and Flipkart sellers after a 2021 Reuters report—based on internal Amazon documents—revealed that the company had secretly given preferential treatment to a small group of vendors, helping them circumvent Indian regulations.

Amazon has denied any wrongdoing.