FWIW - I have no way of verifying this - Telegram says they try to work around this by (IIRC) :

- Using some kind of crypto with multiple keys

- These keys are located in multiple independent datacenters in independent jurisdictions

According to what I read this was supposed prevent leaking of user data just by bribing/coercing/etc or suing any Telegram employee or datacenter provider.

As I've mentioned before I don't use Telegram for security, I use it because

1. Facebook failed its Whatsapp acquisition so badly

2. It is way more user friendly

Also keep in mind that when I left WhatsApp for Telegram WhatsApp still didn't have e2e.