Fairfax Media understands the pair - a 51-year-old man and a 39-year-old woman - were stopped at Sydney International Airport after officers identified them for a targeted baggage examination.

Upon inspection, Australian Border Force officers discovered five packets of milk powder and two heat packs in their luggage, each of which were found to contain a pink or orange powder, which allegedly tested positively for pseudoephedrine.

The findings totalled 7.7 kilograms - enough to produce 75,000 hits of ice - with a street value of more than $7 million.

The couple, Taiwanese nationals, were taken to Mascot Police Station and charged with importing a border-controlled precursor. Both were refused bail.

Pseudoephedrine, most commonly found in cold and flu tablets, is used as a precursor agent in the production of methamphetamines, including ice.

"This interception is the result of our officers' constant vigilance in ensuring that illicit products do not enter into Australia and make their way onto our streets," NSW Regional Commander Tim Fitzgerald said.

"The ABF is constantly on alert at Australia's borders and, in cooperation with our law enforcement partners, we continue to use intelligence and specialist detection techniques to combat the threat of illicit drug importation on a daily basis."

The couple, who appeared in Central Local Court on April 7, are due to reappear on June 1. They face a maximum of five years' imprisonment, a fine of $180,000, or both.