insider

US /ɪnˈsaɪ.dɚ/
UK /ɪnˈsaɪ.dɚ/
"insider" picture
1.

informante, persona de adentro

a person within a group or organization, especially someone who has special knowledge or access to information not available to outsiders

:
As an insider, she knew all the secrets of the company.
Como informante, conocía todos los secretos de la empresa.
The police suspect an insider helped the thieves.
La policía sospecha que un informante ayudó a los ladrones.