The communications app TeleMessage, which was spotted on former US national security adviser Mike Waltz's phone, has suspended “all services” as it investigates reports of at least one breach.

TeleMessage lets users archive their chats in secure messaging apps. The hacker found that TeleMessage’s archived chat logs aren’t end-to-end encrypted, allowing them to access the contents of certain messages,

Mike Waltz, the national security adviser for President Donald Trump, is seen in photos using Signal during a Cabinet meeting on April 30.