Ο Νταν ήταν ένας τυφλοπόντικας που πώλησε ακρώς απόρρητες πληροφορίες στη βρετανική κυβέρνηση.

English Translation

Dan was a mole selling top secret information to the British government.

This sentence has been deleted by the Tatoeba admin. The English ‘mole’ is a well-known idiom for ‘spy embedded within opposition ranks’, but I believe that the Greek τυφλοπόντικας refers only to the animal.