The whistleblower Edward Snowden may testify against the US National Security Agency in a German parliamentary investigation.
The revelation was made by German politician Hans-Christian Ströbele, who met with Snowden on Thursday to discuss his involvement in any future investigation by the Bundestag.
Ströbele, Green party candidate for Berlin's Kreuzberg district, said that Snowden was prepared in principle to assist a parliamentary inquiry, according to Bloomberg.
The German politician returned from the meeting with a letter from Snowden addressed to German chancellor Angela Merkel, which will be read out in public this afternoon.
Ströbele warned Snowden would likely face legal complications if he were to travel to Germany from Russia, where he has been granted asylum after leaking documents on mass surveillance by the NSA.
If Snowden were to travel to Berlin, he would be able to apply for asylum in Germany. In June his application for asylum in the country was rejected because he was required to apply in person inside Germany.
Snowden could be granted a residence permit in Germany under paragraph 22 of German residence law, which allows a permit to be granted "if the interior ministry declares it to be in Germany's political interest".
German lawmakers have been calling for a parliamentary investigation into the NSA's surveillance activities following revelations last week that the agency may have tapped Chancellor Merkel's mobile phone.
The Guardian reports that a range of German politicians are supporting calls for Snowden to stand as a witness should an investigation be held.