Incorrect ASN output

[ghost]

Hello,

When using the site, the ASN supplied isn't the announcing ASN, I see that this system relies on a database and that this may be the restriction, but it isn't very accurate, for example, you may try:
2a0d:2582:\100::1, This is announced by my ASN - AS211367, But it's outputted as being AS212877, which is the company I rent the IPv6 off of.

I'm just wondering if there are more accurate ways to do the ASN lookup, maybe querying the RIPE Database or using the Team-Cymru IP to ASN mapping (of which is used in several major programs already)