(CNN) -- Moscow claims an American diplomat tried to recruit a spy for the United States, calling it a "Cold War" provocation. But the timing may indicate the allegation could be linked to fallout over Russian information-sharing about a Boston Marathon bombing suspect.
Russia said Tuesday that Ryan Christopher Fogle, a political officer at the U.S. Embassy, was caught trying to recruit a Russian intelligence officer.
He was shown in videos and still photos released by the Russian security service, FSB, that got wide play in Russian media and brimmed with the stuff of spy novels.
In one video, Fogle is shown face down on the street and then is hustled into a car and driven away.
Fogle then enters a room and passes a table displaying his "spy arsenal" -- wigs, recording devices, what appears to be a stack of Euros, a knife, and plastic bags with documents.
The Russian Foreign Ministry warned that the incident not only exposed "a foreign agent who was caught red-handed" but also raised "serious questions" for the United States.
"While the presidents of our countries reaffirmed their readiness to expand bilateral cooperation, including the cooperation of intelligence agencies in fighting international terrorism, such provocative actions in the spirit of the 'Cold War' do not contribute to building mutual trust," the ministry said.
It summoned U.S. Ambassador Michael McFaul but the embassy made no public comment.
The CIA also refused to comment.
State Department spokesman Patrick Ventrell was tight-lipped.
"We can confirm that an officer at the U.S. embassy in Moscow was briefly detained, and was released," he said.
Fogle's case comes at a delicate time as Russian and U.S. intelligence services have been cooperating in the investigation of the April 15 marathon bombing that killed three people and injured more than 260 others.
Moscow provided the first intelligence information to the United States about one of the suspects, Tamerlan Tsarnaev, before he visited Russia last year. But recently, Russian authorities have been criticized for not telling the United States all it knew.
Now, the FSB could be retaliating for that criticism.
In the YouTube video released by RT television, an FSB official says the officer Fogle allegedly sought to recruit was "involved in fighting terrorism in the Northern Caucasus" which is the part of Russia where Moscow claims Tamerlan Tsarnaev -- who died days after the attack -- met with Islamic extremists.
Also in the YouTube video, the FSB officer angrily tells Fogle: "At first we didn't believe that this could happen. Because you know perfectly well that recently, the FSB is actively helping in the investigation of the bombing in Boston, and on other information that presents a threat to the security of the United States of America."
Raising his voice and gesturing, the officer recalls the recent visit of FBI Director Robert Mueller to Moscow and conversations between Presidents Vladimir Putin and Barack Obama, who he notes have tried to improve cooperation between the United States and Russia.
"We think, under today's conditions, when our countries are reaching a new level of relations, when the presidents of these two countries are trying to improve the climate of mutual understanding between the two governments, this citizen -- in the name of the U.S. government -- commits the most serious crime here in Moscow," he says.