Focke-Wulf Ta 183 Huckebein
I have just read this passage on Wikipedia about the FW Ta 183:
In early 1944, the Reich Air Ministry (RLM, for Reichsluftfahrtministerium) became aware of Allied jet developments, and were particularly concerned that they might have to face the Gloster Meteor over the continent. In response, they instituted the Emergency Fighter Programwhich took effect on July 3, 1944, ending production of most bomber and multi-role aircraft in favour of fighters, especially jet fighters.
https://en.m.wikipedia.org/wiki/Focke-Wulf_Ta_183
How would the RLM have found out about the Meteor development?