Taken from this web-page: The arrest of Constantin Diamandy, Romania’s plenipotentiary minister in Petrograd, on Lenin’s order.
On the evening of December 31, 1917 (January 13, 1918, new style), the plenipotentiary minister of Romania in Petrograd, Constantin Diamandy, and the staff of the Royal Legation of Romania were arrested by the Bolsheviks, under Lenin’s order, and taken to the St. Peter and Paul prison. This unusual incident in the diplomatic world was the reply of the Soviet government to the tensions between the Romanian army and the Russian soldiers in Moldavia.
The soldiers of the 194th regiment of the Russian 49th Division, who were stationed between the cities of Bacău and Roman, near the front line, came into conflict with the Romanians, and were ordered on December 27, 1917 to lay down their weapons. The Russians refused and threatened to use force to reach Roman, in order to release a Bolshevik leader held by the Romanians. The Romanian army was forced to open fire. Several Russian soldiers were injured, the rest were disarmed by the Romanians or fled. The disarmament of Soviet troops attracted a harsh and unusual response from the Soviet government. The arrest of the Romanian Plenipotentiary Minister in Petrograd provoked protests from the entire foreign diplomatic corps in Russia.
Following the protest of the diplomatic corps accredited to Petrograd, after two days of detention under humiliating conditions, Constantin Diamandy received a note from the Soviet government conditioning his release and that of the personnel of the Royal Romanian Legation with the release of the Russian troops detained on the front. However, Romania’s plenipotentiary minister in Petrograd refused any negotiations: “I replied that I would not accept that my release be subjected to any condition and that, in the context of such a horrendous violation of International Law, I would absolutely refuse to negotiate state issues while incarcerated”.
Constantin Diamandy agreed to leave the prison only after writing a report stating clearly that he refused any negotiations with the representatives of the Russian government. After his release, Diamandy was expelled from Russia, and the Soviet government decided to break diplomatic relations with Romania (January 13/26, 1918) and to seize the Romanian Treasure, located in Moscow.
The Soviet of the People’s Commissars of the Russian Soviet Federative Socialist Republic claimed that Constantin Diamandy’s arrest “for a short time” took place “in protest” against “the crimes of the Romanian military and civil authorities”.