A public prosecutor in the German city of Hanover announced on Thursday evening that it was applying for the lifting of President Christian Wulff's immunity from legal proceedings.

In a statement, the prosecutor's office said that extensive evaluation of documents and media reports allowed for an "initial suspicion" that Wulff may have improperly received and granted benefits.

Wulff has been under fire over his ties to provincial businessmen during his time in office as premier of Lower Saxony state.

It is the first time a move has been made to lift the president's immunity and begin an investigation.

Long-running scandal

Since mid-December, the president has been in the media spotlight for financing a house with cheap loans from the wife of a businessman friend. The president has already apologized for failing to disclose that he had borrowed the money.

He also has been criticized over an angry call he made to the editor of German mass-circulation daily Bild before it published new findings about the loan.

The investigation was said to be in connection with businessman David Groenewold, a businessman friend with whom Wulff and his wife stayed while on holiday on the German island of Syllt.

Opposition ready to vote

However, the prosecutor would only begin be able to bring proceedings against the German president if lawmakers in the Bundestag - Germany's lower house of parliament where Chancellor Angela Merkel's ruling coalition has a majority - agrees to the lifting of immunity.

Merkel has so far stood by Wulff

Opposition politicians have indicated their readiness to do just that. In Friday's edition of the Passau Neue Presse newspaper, the Social Democrats' general secretary, Andrea Nahles, said Wulff should step down.

"It has never happened before that German prosecutors considered it necessary to investigate a head of state," she said. "In my eyes, an investigation by the public prosecutor is incommensurate with the office of the president."

The heads of the Green Party parliamentary faction, Renate Künast and Jürgen Trittin, also said on Thursday evening that it was time for Wulff to go.

"In this situation, the president must, at the very least, step aside," the politicians said on Thursday in Berlin. "We will do everything we can to make sure that his immunity will be lifted as soon as possible."

Surveys show the mainly ceremonial president's popularity falling, although Merkel, who nominated him, has been largely unscathed by the series of revelations.

mz,rc/slk (dpa, dapd)