When you're drinking from a carton of orange juice,Watch Psych 2: Lassie Come Home Online pretty much the only thing you want to discover inside that carton is orange juice.

Certainly not any foreign objects.

And certainly not any foreign objects that look like this:

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Esme Moser from London posted that tweet on Tuesday, complete with a fairly disturbing close-up of the mystery object in question:

Sainsbury's, the British supermarket from which she purchased the carton, have since been in touch with her to get to the bottom of the issue.

A spokesperson explained to Mashablethat they've looked into the images, and what the pictures actually show is mould.

“Although it’s rare, a lack of refrigeration, damage to the carton, or drinking repeatedly from the carton could cause mould growth," they said.

"We are arranging a gesture of goodwill for the customer."