The Guardian’s Glenn Greenwald will testify before a bipartisan congressional group next week about the National Security Agency’s surveillance program, he confirmed to POLITICO.

The hearing will take place on Wednesday and comes amid growing congressional concern over the reach of the NSA’s surveillance tactics. It will be headed by Democratic Rep. Alan Grayson.

According to the Guardian’s report, Greenwald will testify via video-link from Rio de Janeiro, Brazil.