US President Donald Trump has authorized the release of a controversial memo. The document accuses the FBI of abusing its surveillance powers of investigation, into whether Trump's presidential campaign colluded with Russia in election meddling. CGTN's Nathan King brings us more from the White House.

"It's a disgrace- what's going on in this country is a disgrace." U.S. President Donald Trump's reaction after he cleared for release a controversial memo alleging surveillance law abuses It was written by this man Devin Nunes, a Trump political ally, who is head of the intelligence committee in the U.S. House of Representatives.

After reading secret documents, Nunes wrote this four-page memo in which he alleges that the investigation into the Trump campaign's links with Russia was flawed because he claims 'Officials used unverified dossier on Trump to help obtain surveillance warrant on Trump operative; Officials did not disclose dossier was partly funded by Hillary Clinton's campaign; Law enforcement officials leading the probe were biased'.

The memo was based on classified information so it was up to U.S. President Trump to authorize its release. In a tweet, he claimed it revealed bias at the top of the FBI and Justice Department. He wrote 'The top Leadership and Investigators of the FBI and the Justice Department have politicized the sacred investigative process in favor of Democrats and against Republicans, something which would have been unthinkable just a short time ago. Rank and File are great people'.

The release of the controversial memo pits the U.S. president against the leadership of the FBI, the Justice Department and the U.S. intelligence agencies. Trump's critics argue he's doing this to cast doubt over the investigation into his campaign's ties to Russia and possible obstruction of justice.

Many of those Trump is accusing of bias are his appointees- including Republicans. The FBI suggested the memo is misleading and issued this unprecedented statement before its release saying 'the FBI was provided a limited opportunity to review this memo the day before the committee voted to release it. As expressed during our initial review, we have grave concerns about material omissions of fact that fundamentally impact the memo's accuracy'.

Trump's political opponents, the Democrats agree, and say the memo may be used as an excuse by President Trump to fire the special counsel looking into his campaign's ties to Russia- Robert Mueller was appointed by the very Justice Department officials criticized in this memo.

Mueller was once the head of the FBI himself and is a Republican. But Trump has already fired one head of the FBI since taking office- many fear another political purge may be coming. Nathan King, CGTN, Washington.