illegitimately
US /ˌɪl.ɪˈdʒɪt̬.ə.mət̬.li/
UK /ˌɪl.ɪˈdʒɪt̬.ə.mət̬.li/

1.
in a way that is not allowed by law or rules
:
•
He acquired the property illegitimately.
•
The funds were transferred illegitimately.
2.
in a way that is not in accordance with accepted standards or rules
:
•
His actions were illegitimately motivated by personal gain.
•
The decision was made illegitimately, without proper consultation.