The affair that has Germany's intelligence community embarrassed got under way when it surfaced that the country's Federal Intelligence Service, or BND, read e-mail correspondence between Susanne Koelbl, a German investigative journalist from news magazine Der Spiegel, and an unidentified Afghan politician.

Lawmakers protested, because it was not the first time the BND had been caught spying on journalists: In 2006 a parliamentary report acknowledged that intelligence agents had illegally spied on journalists, with BND spies having picked through journalists' garbage to reveal their sources.

And Koelbl may not be alone: The Berliner Zeitung newspaper reported Thursday that a German diplomat in Kabul warned a prominent German TV journalist on assignment in Afghanistan that he is being monitored.

"At that moment I knew that the laws that protect me in Germany are being ignored in a foreign country," he told the newspaper.

That's one reason why the latest revelation caused a stir, with BND head Ernst Uhrlau personally apologizing to Koelbl earlier this week. Yet when lawmakers dug deeper, interrogating Uhrlau Wednesday and Thursday in a session of a parliamentary committee tasked with controlling the intelligence services, the BND head revealed that not Koelbl, but the Afghan politician she had exchanged e-mails with was the actual target of the surveillance operation. On Thursday, his name first appeared on the news tickers: Afghan Economy Minister Mohammad Amin Farhang, who has lived in Germany in the past. BND spies in Afghanistan apparently installed spy software on Farhang's computer, monitoring his e-mail correspondence.

It remains unclear why the BND surveyed Farhang, but the Afghan government in Kabul has since demanded an explanation. Der Spiegel said Farhang has been an important source for stories coming out of the war-torn country. Observers speak of an embarrassing affair that could trouble Afghan-German relations.

Within Germany, the case is also making waves.

"The trust between the (parliamentary commission) and the leadership of the BND has been violated by this," the commission probing the case said in a statement, calling the spy operation on Farhang and the journalist "a grave breach of basic rights."

The whole story is even more explosive as it uncovers serious internal differences the BND will have to overcome in the coming months. Apparently, Uhrlau was not informed of the operation until a year after its end. The committee criticized Uhrlau of not having informed the government immediately afterward.

Conservative and Green Party lawmakers have since called for Uhrlau's resignation; others say that won't improve the internal situation of the BND.

"One shouldn't be too hasty when it comes to the consequences" this affair will have for Uhrlau, opposition lawmaker Max Stadler told German news channel n-tv. "But one thing is important: Basic rights don't cease to exist at the German border. They are to be adhered to when Germans communicate, telephone or e-mail with foreign partners.

"We are very worried that the BND leadership has lost control over some of its agents."