BERLIN (AP) A German lawmaker says he has met Edward Snowden in Moscow, and that the National Security Agency leaker is prepared in principle to help Germany investigate allegations of surveillance by U.S. intelligence.

Hans-Christian Stroebele says the meeting happened Thursday. He posted on Twitter a picture of himself with Snowden.

The lawmaker from Germany's opposition Greens is a prominent critic of the NSA's alleged actions. He told ARD television that Snowden "made clear he knows a great deal" and he would be prepared to travel to Germany and testify "but the circumstances would have to be cleared up."

Germany is seeking answers from U.S. authorities to allegations Chancellor Angela Merkel's cellphone was monitored.

Stroebele says Snowden gave him a letter to German authorities that he'll present in Berlin on Friday.