An official who helped steer East Germany's communist party into democracy after the Berlin Wall fell, Lothar Bisky, has died aged 71, a political ally says.
His death on Tuesday coincided with the 52nd anniversary of the start of construction on the despised Wall.
Bisky was a member of the European Parliament for the far-left Linke party.
Its German parliamentary group leader, Gregor Gysi, announced his death "with deep sadness" in a statement.
The cause of death was not immediately known.
Bisky led the Party of Democratic Socialism (PDS), the immediate successor to East Germany's communist party after national reunification, from 1993 to 2000, and again from 2003 to 2007.
After the party merged with a small left-wing outfit from the west to become the Linke, he served as co-chairman with former finance minister Oskar Lafontaine until 2010.
A fierce defender of easterners' interests as the region weathered the economic upheaval from the transition to capitalism, Bisky nevertheless suffered a dent to his reputation when it emerged in 1995 that he had worked as an informant for the Stasi secret police.
Born in Pomerania in today's Poland, he fled the region with his family after WWII for northern Germany.
He moved to the German Democratic Republic, as the communist state was known, to pursue university studies and joined the ruling Socialist Unity Party in 1963, two years after the Wall went up.
Bisky went on to become a professor of film and television, and worked briefly for public television after reunification in 1990.
He took over the leadership of the PDS from fellow moderate Gysi in 1993, and approved a party platform the next year that broke with the hardliners and promised a "leftist democratic alternative" to the conservative government of then chancellor Helmut Kohl.
