The scandal surrounding Jack Abramoff claimed another political career on Friday after a former senior member of the Bush administration pleaded guilty to obstructing a Senate investigation into his relationship with the Republican super-lobbyist.

James Steven Griles, the former second-ranking official within the Department of the Interior, has admitted to lying to the Senate committee on Indian affairs, which, under the then-chairmanship of Senator John McCain, led a probe into allegations that Mr Abramoff, who is serving a 70-month prison term, had “undue influence” at the department.