John Raoux / PA Wire John Raoux / PA Wire / PA Wire

FBI INVESTIGATORS SO far have not found persuasive evidence that Orlando gunman Omar Mateen was pursuing gay relationships, according to two government officials familiar with the investigation.

The FBI began investigating that possibility after media reports last week quoted men as saying that Omar Mateen had reached out to them on gay dating apps and had frequented the gay nightclub where the June 12 massacre took place. One man even claimed to be Mateen’s gay lover in an interview with Univision that aired this week.

But the officials say the FBI, which has recovered Mateen’s phone and conducted 500 interviews, has not found concrete evidence nearly two weeks into the investigation to corroborate such accounts. They also say the investigation is ongoing and that nothing has been formally ruled out.

The officials were not authorised to discuss an ongoing investigation by name and spoke on condition of anonymity.

Omar Mateen MySpace via AP, File MySpace via AP, File

Law enforcement officials have said they believe Mateen was radicalised at some point before the Pulse nightclub attack. In calls with the police after the shooting began, he pledged his allegiance to the leader of the Islamic State and declared himself to be an Islamic soldier.

Attorney General Loretta Lynch has taken pains not to describe radical extremism as the sole motivation and declined in an interview with The Associated Press on Tuesday to rule out any possibility, including that he was secretly gay. She also declined to say what evidence, if any, existed to support alternate theories.

In the interview and in later remarks to reporters, she called the attack that killed 49 people an act of both terror and hate:

While we know a lot more about him in terms of who he was and what he did, I do not want to definitively rule out any particular motivation here. It’s entirely possible that he had a singular motive. It’s entirely possible that he had a dual motive.

Mateen had a wife who has been extensively interviewed by federal investigators.

Read: Orlando gunman’s ‘gay lover’ claims massacre was revenge against HIV-positive partner >