The Iranian government has expelled a German diplomat.
The unnamed person had been carrying out "non-diplomatic activities", a foreign ministry spokesman said. He gave no further details.
The German foreign ministry said the diplomat had recently left Tehran after being ordered out of the country, but did not elaborate.
The German magazine Der Spiegel last month reported that Berlin had expelled an Iranian consular attache.
The paper said he had tried to buy a component that could be used for enriching uranium.
The German foreign minister did not comment on that report.
Germany is one of three European powers negotiating with Iran over Tehran's controversial nuclear program.