Indian authorities on Wednesday halted production at a pharmaceutical factory under investigation over the deaths of 66 children in The Gambia, according to local media.

The World Health Organisation last week warned that four cough and cold remedies manufactured by Maiden Pharmaceuticals in the northern state of Haryana could cause acute kidney injury.

Laboratory testing found "unacceptable amounts" of potentially life-threatening contaminants, the WHO said, adding that the products may have been distributed beyond the West African country.

"We have ordered that all drug production at this unit be stopped with immediate effect," Haryana state health minister Anil Vij was quoted as telling Indian news agency PTI on Wednesday.

The minister added that a preliminary inspection found 12 violations at Maiden's facility in the town of Kundli, about 40 kilometres from the capital New Delhi.

Maiden Pharmaceuticals director Naresh Goyal has reportedly denied the deaths were caused by cough syrups produced at his company.

"The deaths have been due to paracetamol syrup and not due to our cough syrups," he told India's Economic Times newspaper.

Police in The Gambia on Saturday said they were launching their own investigation into the children's deaths.

India's health ministry last week said it had been informed of the WHO's findings and was awaiting the results of its own lab tests on the four products.

It added that the company was not licensed to distribute the four medicines in India and had only exported them to The Gambia.

"It is a usual practice that the importing country tests these imported products on quality parameters, and satisfies itself as to the quality," a ministry statement said.

Maiden Pharmaceuticals did not respond to AFP requests for comment after the WHO issued its health alert.

The company has caught the attention of Indian regulators several times before.

The Food and Drug Administration has issued notices to the firm four times this year over "substandard" manufacturing based on batch tests, according to the agency's website.