Who is Sonic's real brother?

Can you tell me, with all due respect, who exactly is Sonic's true brother in the Sonic the Hedgehog universe? Is there a canonical character that has been established as his sibling, or is this a question that fans have debated among themselves without a definitive answer? I'm genuinely curious about the origins of this query and whether there's any official information that can shed light on the matter. Thank you for your time and consideration.