Also joining the usually British-based music and comedy festival is actor Tim Roth and British comedians Matt Berry and Jimmy Carr. Among American comedians are "Saturday Night Live" cast member Bobby Moynihan, Taran Killam and Jay Pharoah ,as well as "Entourage" actor Rex Lee.

The concert, which will benefit Amnesty International on the 50th anniversary of the human rights group, will feature previously announced big names and acts including Coldplay, Jon Stewart, Russell Brand, Paul Rudd, Stephen Colbert and Mumford & Sons among a total of 36 entertainers.

"The Secret Policeman's Ball has a long and glorious tradition of helping Amnesty International to take on tyrants through world-class comedy," said Kerry Moscogiuri, director of marketing for Amnesty International.

"As Amnesty International brings the Ball to the United States for the first time, the headlines around the world - from Syria to China - demonstrate just how much Amnesty's work is needed," she added.

Myanmar comedian and director, Zarganar, will also perform at the show that was first staged in 1976. Zarganar was released last year after being sentenced in 2008 to 59 years in a remote prison after criticizing then-ruling generals for their sluggish response to Cyclone Nargis.

The concert's head writer David Javerbaum, the former head writer and executive producer for "The Daily Show with Jon Stewart," called the final line-up "a pretty unbelievable collection of comedic and musical talent."

The show, last held at Royal Albert Hall in 2008, aims to celebrate free speech and raise awareness for Amnesty International. It will feature sketches, music and other acts.

(Reporting By Christine Kearney; editing by Patricia Reaney)

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