Omar Mateen
Omar Mateen's exact words became a political controversy after the FBI's first release of a transcript of his phone calls.Reuters

An official law enforcement transcript of Omar Mateen's phone calls made during his mass shooting at an Orlando LGBT nightclub got political, when Republicans furiously complained that the wording of the transcript was edited to remove his vow of allegiance to the head of the Islamic State (Isis) reports claimed on Monday 20 June.

At one point in a call to the emergency number 911, made during the attack, Mateen pledged his loyalty to Isis leader, Abu Bakr al-Baghdadi. But according to some, that was initially redacted in the partial transcript released by the feds.

The FBI capitulated to criticism by releasing a full transcript of his first emergency call.

"Praise be to God, and prayers as well as peace be upon the prophet of God," Mateen said in Arabic in the call to a 911 dispatcher. "I wanna let you know, I am in Orlando and I did the shootings."

He added in Arabic: "I pledge allegiance to [Isis leader] Abu Bakr al-Baghdadi. May God protect him on behalf of the Islamic State." In another call to crisis negotiators Mateen warned of similar attacks in the coming days and said he had a suicide vest similar to the ones "used in France."

According to the FBI's first transcript, which included paraphrasing, Mateen "identified himself as an Islamic soldier who pleaded allegiance to a terrorist organisation intent on killing Americans." There was no mention of Isis or the Islamic State. He also told crisis negotiators "to tell America to stop bombing Syria and Iraq," according to the early transcript.

Republican House Speaker, Paul Ryan, called the initial decision to edit the transcript to remove mention of Isis "preposterous," reported USA Today.

"We know the shooter was a radical Islamist extremist inspired by Isis,'' Ryan said. "We also know he intentionally targeted the LGBT community. The administration should release the full, un-redacted transcript so the public is clear-eyed about who did this, and why.''

Mateen's motivation is at the heart of a political controversy over the attack. The FBI is attempting to determine if he was truly motivated by Isis (Daesh) or if the attack was more profoundly driven by a hatred of gays, possibly affected by his own confused sexuality, veiled behind a violent political movement.

An agent initially said the FBI was "not going to propagate violent rhetoric" by giving full transcripts with no redactions, CBS News reported.

Republicans view Mateen, an American citizen born in the country, as being clearly driven by Islamic radicalism.

There was apparently no contact between Isis and "lone wolf" shooter Mateen, officials believe. But Isis later released a videotape praising Mateen as "one of the soldiers of the Caliphate," and"one of the few who was truthful to his lord."

"The purpose of releasing the partial transcript of the shooter's interaction with 911 operators was to provide transparency, while remaining sensitive to the interests of the surviving victims, their families, and the integrity of the ongoing investigation," the FBI and Justice Department said in a joint statement.

Authorities also edited the transcript because they "did not want to provide the killer or terrorist organisations with a publicity platform for hateful propaganda," according to the statement.

But officials finally opted to reveal the full transcript after the criticism because "unfortunately, the unreleased portions of the transcript that named the terrorist organizations and leaders have caused an unnecessary distraction from the hard work that the FBI and our law enforcement partners have been doing to investigate this heinous crime."

Here's the 'unredacted' transcript of Mateen's call to 911:

White House press secretary Josh Earnest said all decisions about the release of the transcript were made by the Justice Department and that the president had nothing to do with steps being taken.

"The position of the White House is that we shouldn't interfere with a pending law enforcement investigation," he said.

Authorities will not release audio recordings of Mateen's phone calls. But FBI agent, John Hopper, who is charge of the investigation, described Mateen's voice as "chilling, calm and deliberate."

Officials said Mateen also made three calls to crisis negotiators during the attack, and that police attempted to call him back. The shooter also made a "goodbye" call to a friend, called a local television station, made posts to Facebook and exchanged texts with his wife while holed up in the club.