US Actress Alyssa Milano has blasted officials at London's Heathrow after her breast milk was confiscated Europe's busiest airport.

The 42-year-old star, best known for playing Phoebe in TV series Charmed and Savannah in Mistresses, fell foul of the stringent 100ml rule for taking liquids in hand luggage when she prepared to leave the capital on Thursday (9 March).

In a string of tweets, Milano, who gave birth to her second child seven months ago, said that she was "not Okay" with the incident.

She also questioned why her shampoo and other lotions with more ounces of liquid were no problem yet her baby milk was what was taken.

Airport guidelines, introduced in 2006 in response to fears that terrorists could use liquid explosives, state: "If you're travelling with a baby you can bring prepared milk and expressed milk in cartons or bottles over 100ml."

Heathrow Airport's official Twitter account responded to her social media tirade informing her that "Unfortunately, without a baby present, the government requires all liquids in carry-ons to follow the 100ml rule."

But Milano was unsatisfied with the company's comeback and promptly revealed that she was preparing to take action after her breast pump had gone missing.

"Everything arrived at my final destination except my hospital grade breast pump. Filling out a lost baggage claim now," she said.

She has since won over support from other parents who hailed her for raising awareness for breast-feeding mums.

"I applaud you @Alyssa_Milano for making a statement for all breastfeeding mommies out there! Hope you and your beautiful family is well x" one fans said.