General Antonyms:
* Concealed: To hide or keep secret.
* Suppressed: To put down or prevent from being known.
* Denied: To refuse to acknowledge or accept.
* Withheld: To hold back or refrain from giving.
* Ignored: To pay no attention to.
More Specific Antonyms:
* Withdrawn: To take back a statement.
* Recanted: To take back a statement, especially a confession.
* Disavowed: To deny responsibility for or connection to something.
* Refuted: To prove something false or incorrect.
* Disproved: To show that something is not true.
The best antonym will depend on the specific situation and the meaning of "proclaimed" in that context.