Then US vice-president Joe Biden with his son Hunter in Beijing in December 2013. Photograph: Andy Wong/EPA Then US president Barack Obama greets vice president Joe Biden and his son Hunter at a college basketball game in Washington in January 2010. Photograph: Alexis C Glenn/EPA Hunter Biden’s business interests often show up in unexpected places. Now, they are at the centre of the biggest political crisis of the Trump presidency and the fourth impeachment inquiry in US history. The son of Joe Biden, former vice-president and 2020 presidential candidate, Hunter Biden’s business ties are under scrutiny after Donald Trump leaned on the president of Ukraine to investigate his activities in the country. Trump has also publicly called on China to investigate the Bidens. The Ukraine revelations have led House Democrats to open an impeachment inquiry against the president, but the nature of Hunter Biden’s business dealings in Ukraine, China and further afield raise questions about potential conflicts of interest while his father was in office. The Bidens have denied any wrongdoing. In addition to his ties to Ukraine through Burisma, the scandal-plagued gas company, and politically con...