Top US senator promises Trump 'coup' probe

Updated February 18 2019 - 10:46am, first published 10:40am
Lindsey Graham will investigate allegations the US Deputy Attorney General discussed ousting Trump.
Lindsey Graham will investigate allegations the US Deputy Attorney General discussed ousting Trump.

A prominent US Republican senator allied to Donald Trump has promised to investigate allegations Deputy Attorney General Rod Rosenstein discussed trying to oust the president from office in 2017.