WASHINGTON (AP) – Two government officials familiar with the Orlando shooting say FBI investigators have so far not turned up persuasive evidence that the gunman was pursuing gay relationships.

The FBI began investigating the possibility after media reports quoted men as saying that Omar Mateen had reached out to them on gay dating apps and had frequented the Pulse nightclub. One man claimed in an interview with Univision to be Mateen’s gay lover.

But the officials say the FBI, which has recovered Mateen’s phone and conducted 500 interviews, has not been able to corroborate those accounts. They add, however, that the investigation is ongoing and that nothing has been formally ruled out.

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