A man types on a computer keyboard in Warsaw in this February 28, 2013 illustration file picture. REUTERS/Kacper Pempel

WASHINGTON (Reuters) - An alleged computer hacker sympathetic to Syrian President Bashar al-Assad’s government is due to appear in federal court in Alexandria, Virginia, on Tuesday after being extradited from Germany, a U.S. law-enforcement source said on Monday.

The source said Peter Romar, 36, an alleged member of the hacking group Syrian Electronic Army, was being flown to the United States on Monday.

Romar is one of three Syrian nationals charged in March by U.S. federal prosecutors in Virginia with being part of a criminal conspiracy.

Two other defendants in the case, Ahmad Umar Agha and Firas Dardar, were charged with being involved in a “hoax regarding a terrorist attack,” and “attempting to cause mutiny of the U.S. armed forces.”

Dardar and Agha are still believed to be in Syria.

Romar and Dardar were charged separately with extortion and wire fraud. Prosecutors alleged their activities included attempts to blackmail hacking victims and transfer their extortion payments to Syria, with Romar in Germany acting as a middleman, according to a court document.

The alleged hackers used a relatively unsophisticated hacking tactic known as “spear-phishing,” to target computers belonging to media networks, including CNN, National Public Radio, the Associated Press and Reuters, in addition to Microsoft Corp, Harvard University and Human Rights Watch, the U.S. Justice Department said at the time of the indictment.

The group’s most notorious escapade was the hijacking of an Associated Press Twitter account in April 2013, involving the issuing of a message saying the White House had been bombed and President Barack Obama injured. That hack caused a temporary stock market plunge.

The hackers also allegedly tried, unsuccessfully, on multiple occasions to infiltrate the White House data systems.