China's food safety watchdog has asked three milk producers in Shaanxi province to recall infant formula powder, following the detection of excessive nitrate levels in some powdered milk samples, according to BBC World News. Xinhua news agency in China also said the products were branded as sub-standard.

The watchdog urged Shaanxi to punish producers found to have broken laws.

The quality of milk products remains a sensitive topic in China after a deadly tainted milk scandal in 2008. At least six children died and some 300,000 fell ill after consuming milk products contaminated by melamine at that time. Imported milk became highly prized in China after the incident with the majority of China's imported milk powder coming from New Zealand.

This is despite China's mainland imposing a temporary ban on all imports of milk powder from New Zealand in 2013, after its main dairy exporter, Fonterra, found a bacterial strain that can cause botulism in some of its products.

Currenrtly some 10% of global infant formula is sourced in Ireland.

China to recall Shaanxi baby milk powders

According to Chinese state media reports, China's food safety watchdog has asked three milk producers in Shaanxi province to recall infant formula powder.