BONN, DEC. 8 -- A government spokesman said today that documents have been discovered appearing to show that former East German prime minister Lothar de Maiziere, now a minister in Chancellor Helmut Kohl's government, may have been an informer for the Stasi secret police under the code name "Czerny."

De Maiziere, as he did when similar charges surfaced in January, denied ever having informed for the dreaded and now disbanded Stasi.

Government spokesman Dieter Vogel said Kohl summoned de Maiziere to his office Thursday after a committee combing through the voluminous Stasi files reported that a "reference to a document was found on a file card, under the cover name 'Czerny,' with an address" the same as that of de Maiziere in east Berlin.

Kohl and de Maiziere have asked for an investigation of the documents, and Vogel would not comment on the file's authenticity. The Stasi files could contain planted papers intended to incriminate innocent people.

In a statement today, de Maiziere said an investigation last spring by the now-dissolved East German parliament found no evidence that he had any connection to the Stasi. "I only had contact with the Stasi as far as it was required by my work," de Maiziere said. "I signed no commitments, and I received no money or other benefits."

According to an advance text of an article to appear in next week's issue of the German newsmagazine Der Spiegel, the documents indicate that de Maiziere may have provided the Stasi with information about the Protestant church, a relatively safe place for dissidents under the hard-line Communist government.

Before entering politics as the reluctant Christian Democratic candidate for prime minister in East Germany's first vote after the fall of the Communists, de Maiziere was a lawyer for the church, a position in which he often defended dissidents.

One of the documents discovered this week, according to Der Spiegel, says Edgar Hasse, a Stasi major, met with de Maiziere about once a month and received information about the church, de Maiziere's legal work and his connections to leading officials of the West German diplomatic office in East Berlin. The document reportedly dates from September 1988.

Der Spiegel said de Maiziere had worked for the Stasi since 1981. The alleged control officer, Hasse, told the magazine that de Maiziere initiated the relationship, chose his own code name and came to the Stasi voluntarily.

De Maiziere is a former viola player; Carl Czerny (1791-1857) was an Austrian composer.

De Maiziere had been expected to be named to a ministerial-level position in the new government Kohl is organizing after his reelection victory last Sunday.

More than 500,000 of East Germany's 17 million citizens were named in the Stasi files as "informal employees" who informed on their neighbors, friends and co-workers. The secret police was disbanded by the de Maiziere government.