A Russian prankster posing as the UN secretary general, managed to get through to Poland’s re-elected president, Andrzej Duda, on the telephone, rendering him speechless following questions about Ukraine, Russia and the outcome of Sunday’s election. The prankster, Vladimir Kuznetsov, known as Vovan, posted a recording of the 11-minute call on YouTube, and Duda’s office confirmed on Wednesday it is authentic. At various points in the conversation, conducted in English, Duda sounds surprised at the line of questioning but still refers to the fake Antonio Guterres as “Your Excellency.” The conversation was held on Monday afternoon while Duda was awaiting official confirmation of his re-election. State security is investigating how the prankster got through to the president, and whether Russia’s secret services were involved. The Internal Security Agency said in a statement the call had been authorised by a Polish mission official at the UN, and that his actions are under investigation. Poland’s relations with Russia are tense, especially over Warsaw’s support for Ukraine’s drive for closer links with the European Union. The caller congratulates Duda on his re-election but takes him to task on his hostile campaign comments about the LGBT community, drawing Duda’s assurance that he has “huge respect for every human being”. President Duda wins cliffhanger re-election in Poland Duda also rejected any suggestion that Poland would seek to claim back the Ukrainian city of Lviv, that was part of Poland before second world war. Kuznetsov, and the Russian prankster Alexei Stolyarov, who is known as Lexus, have previously embarrassed European politicians including French President Emmanuel Macron and British Prime Minister Boris Johnson, as well as Elton John and Prince Harry, with similar hoax calls.