Evan Gershkovich, a US journalist, has appeared in a Russian court for an appeal hearing that will decide whether he will remain detained before his trial. 

The hearing will determine whether he will still be held in pre-trial detention at Moscow's Lefortovo prison until at least May 29.

Gershkovich, a reporter for The Wall Street Journal, stood in a glass and metal enclosure inside the courtroom on Tuesday, wearing a checked shirt with his arms folded in front of him. He did not say anything.

Russia's FSB security service arrested Gershkovich last month on espionage charges that carry a possible 20-year prison sentence. The United States has deemed him "wrongfully detained". 

This is a breaking story. More to come.