Donald Trump's relationship with Barack Obama descended to a new low over the weekend after the US president made explosive accusations that his predecessor orchestrated an illegal Watergate-style bugging operation at Trump Tower in New York.

The unprecedented attack follows a years-long feud between the two men. We look back at their strained relationship.

'Birther' movement

Donald Trump did not accept President Barack Obama was born in the United States until September 2016 - ending a bizarre eight-year conspiracy theory that his critics say shows Mr Trump to be racist.

Mr Trump revived the "birther" question in an interview with The Washington Post, in which he said he was "not ready" to publicly acknowledge Mr Obama's legitimate right to be president.