WASHINGTON (AP) — The Justice Department's internal watchdog said Wednesday it will examine Republican complaints of FBI misconduct in the early stages of the Russia investigation.

Inspector General Michael E. Horowitz's investigation comes at the request of Attorney General Jeff Sessions and congressional Republicans. They have been urging his office to review whether FBI and Justice Department officials abused their surveillance powers in using information compiled by a former British spy and paid for by Democrats as part of the basis to justify monitoring a former campaign adviser to Donald Trump.

Horowitz said his office will look at those claims, as well as communications among the spy, Christopher Steele, and Justice Department and FBI officials.

Republicans have been fuming about they see as bias within the FBI, while Democrats say the surveillance abuse allegations are designed to undermine special counsel Robert Mueller's sprawling investigation into the Trump campaign's ties to Russian meddling in the 2016 election.

Horowitz's review comes weeks after Republicans on the House intelligence committee released a declassified memo that detailed the use of political opposition research to obtain a warrant to monitor Carter Page, the former adviser to Trump's campaign. The GOP memo describes the department's use of information compiled by Steele in obtaining a secret warrant to monitor Page's communications. Steele's anti-Trump research was paid for by Democrat Hillary Clinton's campaign and the Democratic National Committee.

As the Republicans suggested the FBI may have conspired against Trump, Democrats countered with their own memo that said the FBI only "made narrow use" of that research.

Sessions referred the Republican complaints to the inspector general's office, a move that enraged Trump, who denounced it as "disgraceful" and said Sessions should have ordered his own investigation. Sessions insisted he had taken the appropriate step.

The new investigation comes as the FBI is already under intense political pressure. Horowitz's office has been examining for more than year the FBI's handling of the Hillary Clinton email investigation, an inquiry focused not only on specific decisions made by FBI leadership but also on news media leaks. That investigation formed the basis for the firing of former Deputy Director Andrew McCabe. The inspector general's report, which led to the recommendation from the disciplinary office, has not been released but is expected out soon.