Yes. You only need sufficient reason to believe that there has been a violation of the regulations mentioned in § 2 HinschG and that the reported information is true. There is an explicit prohibition of reprisals or negative consequences against the whistleblower. Reprisals do not only include dismissals, but also the transfer of tasks, exclusion, non-promotion or refusal of a further training measure can constitute reprisals in individual cases. Whistleblowers who deliberately make false reports, on the other hand, have no protection against negative consequences and may be obliged to pay compensation for any damages inflicted.
In case of doubt, your employer is obliged to prove that a negative consequence is not based on the fact that you have given a hint via the whistleblowing portal.