* Greens legislator makes surprise visit to Snowden
* Says Snowden willing to help German probe US surveillance
A German lawmaker said he met Edward Snowden in Moscow on Thursday and the fugitive former U.S. spy agency contractor was willing to come to Germany to assist investigations into alleged U.S. surveillance of Chancellor Angela Merkel.
Hans-Christian Stroebele, a legislator for the opposition Greens party, told German broadcaster ARD it was clear Snowden "knew a lot" and that he would share details of their surprise meeting including a letter from Snowden addressed to the German government and chief federal prosecutor on Friday.
Stroebele, a well-known maverick in German politics, tweeted a photograph of himself and Snowden and ARD showed images of the two shaking hands in a room before their three-hour meeting.
"He made it clear he knows a lot and that as long as the National Security Agency (NSA) blocks investigations..., he is prepared to come to Germany and give testimony, but the conditions must be discussed," said Stroebele.
His trip came a day after top American and German security officials met in Washington to try and ease tensions caused by reports that NSA, for which Snowden worked, monitored Merkel's mobile phone. Germany is a close ally of the United States.
Stroebele, 74, sits on the German parliament's control committee, which monitors the work of intelligence agencies.
Germany's parliament will hold a special session on Nov. 18 to discuss the tapping, and the Greens and far-left Left party have demanded a public inquiry calling in witnesses including Snowden. Stroebele told him he could give evidence from Moscow.
Snowden's revelations about the reach and methods of the NSA, including the monitoring of vast volumes of Internet traffic and phone records, have angered U.S. allies from Germany to Brazil. Admirers call him a human rights champion and critics denounce him as a traitor.
Defence Minister Thomas de Maiziere said on Thursday Berlin was still smarting over the surveillance. "It is clear that trust has been broken and this trust must be restored ... This requires official agreements on which we can depend," he said.
Russian President Vladimir Putin rejected U.S. pleas to send Snowden home to face charges including espionage, instead granting him a temporary asylum in early August which can be extended annually.
However, Putin, a former KGB spy, has said repeatedly that Russia would shelter Snowden only if he stopped harming the United States. That could make it difficult for Snowden to speak to any German parliamentary inquiry.
Gregor Gysi, parliamentary leader of the Left, has said Germany should include Snowden in its witness protection scheme so he could speak before the committee.
Germany's government was one of many that rejected an asylum request from Snowden earlier this year.
A Russian lawyer helping Snowden said earlier on Thursday that under current agreements Snowden cannot reveal secret information while he is in Russia. Snowden's location in Russia has not been disclosed and since July he has appeared only in a handful of photographs and video clips.
Thursday's encounter was Snowden's first known meeting with a foreign politician, and his first known meeting with any specific foreigner other than his father and a group of former U.S. national security officials he met in early October.
Stroebele, a distinctive figure in Germany with his shock of white hair, bright red scarf and common touch, is a lawyer by training and once defended members of Germany's far-left Baader-Meinhof gang that emerged from the student protest and anti-Vietnam war movements in West Germany in the 1960s.