Hershey’s Chocolate is popular in the US, but one unhappy consumer has launched legal action over the amount of slack fill in its packaging. Picture: Jeff Lauterberger/The Wall Street Journal

You open your favourite chocolate bar or packet of confectionary only to feel a little ripped off and disappointed at what’s inside.

One chocolate lover in the US has had enough and has sued over it.

The man from Missouri has launched a lawsuit over the empty space in his packet of Reese’s Pieces Box.

Robert Bratton purchased several boxes of Reese’s Pieces and Whoppers malted milk balls at a store in Columbia in central Missouri for $1 each.

He claims he was persuaded to buy the product based on the size of the box which led him to believe he was getting more than he actually was.

Mr Bratton sued the maker of the product, The Hershey Company under the Missouri Merchandising Practices Act (MMPA), a 50-year-old law aimed at protecting consumers from unfair and deceptive business practices, KCUR reported.

In his complaint, Mr Bratton accused Hershey of under-filling the Reese’s box by around 29 per cent, and the Whoppers box by 41 per cent which he argues is misleading.

In her ruling, US District Judge Nanette Laughrey found that Mr Bratton had “plausibly alleged, at minimum, that the packaging unfairly suggests the boxes contain more product than they actually do, or tends to or has the capacity to mislead consumers or to create a false impression, which is sufficient for purposes of alleging an unlawful practice under the MMPA.”

Hershey’s argued the number of confectionary and the weight are printed on the outside, and shoppers can feel the weight of the box.

It also argued consumers would be able to tell the box rattles and therefore was not full.

Judge Laughrey dismissed the argument and said the cases cited by Hershey’s legal team did not apply in the state of Missouri.

She deferred a decision on whether Mr Bratton could pursue his claims for “unjust enrichment on behalf of others.”