[deny] (all|) knowledge

to claim that one does not possess information or awareness of a specific subject, event, or fact

The witness chose to deny knowledge of the incident when questioned by the police.
The company spokesperson denied all knowledge of the data breach.
He denied knowledge of the confidential company documents that were leaked.
Despite the evidence, he continued to deny all knowledge of the missing funds.
She couldn't deny knowledge of the project's progress when her signature was on the report.