This is a regular verb. It follows the conjugation pattern of the verb hablar.
PresentPresente
El vecino denuncia el ruido a la policía.
The neighbor reports the noise to the police.
PreteritePretérito indefinido
Denunciamos el robo de la bicicleta ayer.
We reported the bicycle theft yesterday.
FutureFuturo
Ella denunciará el problema a la alcaldía.
She will report the problem to the city hall.