Is it from EuroDNS or the registry?
I've had to confirm my passport number to the Italian registry to confirm I am an EU citizen. Which I did without worry.
If it is from EuroDNS, it may be a case of them passing it to the registry to prove you're eligible for ownership of a domain in the extension.
I'm curious to which extension you're maying $260 for? (Or is it something like a .lt for multiple years)