What would actually verify this identity claim?

Start with records that can be authenticated and checked independently, not just a repeated story or a page making the claim. A personnel record, for example, would need a reliable origin and enough detail to match the identities. Without that, the claim remains unverified.

I’d look for a traceable chain of evidence: who produced each document, when it was created, and whether separate records support the same identification. Similarities in names or appearance, and people repeating the allegation, would not establish that two identities belong to one person.

There isn’t enough here to conclude either way. The useful next step is to ask whoever makes the claim for specific, checkable evidence, then see whether it holds up outside sources that simply repeat the same allegation.