What is 'nark' in Italian?

Informatore is an Italian equivalent of 'nark' in the sense of an 'informer'. It's pronounced 'een-fohr-mah-TOH-ray'. The word in Italian is a masculine gender noun whose definite article is 'il' ['the'] and whose indefinite 'uno' ['a, one']. The feminine equivalent is 'informatrice', which is pronounced 'een-fohr-mah-TREE-chay'.