India's food safety regulator said on Thursday it had ordered testing and inspections at all companies making spice mixes, widening an investigation into the sector as global regulators look into suspected contamination in two popular local brands.

Hong Kong last month suspended sales of three spice blends made by India's MDH and an Everest spice mix for fish curry. Singapore ordered a recall of the same Everest mix as well, flagging high levels of ethylene oxide, which is unfit for human consumption and a cancer risk with long exposure.

MDH and Everest products are hugely popular in India and also sold in Europe, Asia and North America, and the companies have said they are safe. Still, U.S. and Australian food authorities said they are gathering more information on the matter, and India had already ordered testing of the two brands' products.

The Indian regulator has now ordered officials to conduct "extensive inspections, sampling and testing at all the manufacturing units", for powdered spices, with a focus on those making curry powders and mixed spice blends for local and foreign sales.

"Each of the product sampled will be analysed for the compliance with quality and safety parameters," the Food Safety and Standards Authority of India said in a statement.

The agency added checks would also be made for any presence of ethylene oxide, whose use is banned in India, and "appropriate actions will be initiated as fit" after testing was completed.

India is the world's biggest exporter, producer and consumer of spices, and its domestic market for the products was valued at $10.44 billion in 2022, according to Zion Market Research.

Beyond MDH and Everest, other major manufacturers include Madhusudan Masala, NHC Foods and consumer giants Tata Consumer Products and ITC.

None of the companies responded to a request for comment.

The Spices Board says India exported spice products worth $4 billion in 2022-23.

The Global Trade Research Initiative, a New Delhi-based think tank, said in a report on Wednesday that rising global scrutiny could put more than half of country's spice exports at risk.

If China decides to implement similar measures as other countries, Indian spice exports could see a "dramatic downturn", the report said.