Kautilya's Arthashastra 4.4.20

4.4.20

yaṃ vā nānālohakṣārāṇām aṅgārabhasmāsaṃdaṃśamuṣṭikādhikaraṇībimbaṭaṅkamūṣāṇām abhīkṣṇakretāraṃ maṣībhasmadhūmadigdhahastavastraliṅgaṃ karmāropakaraṇasaṃsargaṃ kūṭarūpakārakaṃ manyeta taṃ sattrī śiṣyatvena saṃvyavahāreṇa cānupraviśya prajñāpayet //

Whoever is suspected of manufacturing counterfeit coins in that he often purchases various kinds of metals, alkalis, charcoal, bellows, pincers, crucibles, stove, and hammers, has his hands and cloths dirty with ashes and smoke, or possesses such other accessory instruments as are necessary for this illegal manufacture, may be requested by a spy to take the latter as an apprentice, and being gradually betrayed by the spy, such person, on proclamation of his guilt as the manufacturer of false coins, shall be banished.