There is no evidence Orlando shooter Omar Mateen used gay dating apps and websites, a report claims.

The FBI has spent 11 days raiding the 29-year-old's phone, computer and online accounts to map out a motive for his attack on Pulse nightclub that killed 49 people and injured 53.

Since the shooting, scores of people have claimed Mateen frequented gay bars and messaged men on Grindr.

One man even gave an interview to Univision, claiming he was Mateen's lover for two months last year, and that the hotel where they met - Ambassador - has CCTV footage to prove it.

But according to the Sun Sentinel, federal authorities have found no evidence Mateen was hiding a gay life online.

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Omar Mateen is the gunman who killed 49 people in Pulse. The FBI say there is no evidence he used gay apps

The report says detectives will not stop pursuing the theory.

However, they have yet to find anything concrete to corroborate it.

It comes a day after a man claiming to be Mateen's lover said Mateen was livid after discovering he'd had sex with an HIV-positive man.

The Hispanic gay man, identified only as Miguel, told Univision he met Omar Mateen on Grindr before they became 'friends with benefits', meeting up 20 times at a hotel in Orlando, Florida.

Miguel described Mateen as a confused gay man and a heavy drinker who was attracted to - but felt rejected by - Latinos.

He believes Mateen's massacre on Pulse nightclub's Latin Night was an attempt at 'revenge' after discovering that one of the two Puerto Rican gay men he'd had a threesome with was HIV-positive.

Speaking in fluent Spanish and broken English, Miguel said that despite tests coming up negative, Mateen feared not enough time had passed for an accurate result, and he wanted to 'make them pay'.

Omar Mateen was quietly buried this week in the Muslim Cemetery of South Florida in Hialeah Gardens, a city in Miami-Dade County, according to a state death certificate read by the Orlando Sentinel.

Mateen, 29, was killed by police after he took hostages during a three-hour standoff inside the Pulse nightclub.

The massacre took place during a Latin night celebration at Pulse, which was planning a Latin night street party on Thursday to benefit employees of the club.

Pulse has been closed since the shooting.

'Tryst': The Hispanic gay man, identified only as Miguel, told Univision he met Omar Mateen on Grindr before they became 'friends with benefits', meeting up 20 times at a hotel. His identity has been disguised with a mask

Several media organizations filed a lawsuit on Thursday seeking to force the city of Orlando to release 911 calls and other communications relating to the attack.

Noting the massacre was the latest in a series of mass shootings in the United States, the lawsuit said there was a strong public interest in fully evaluating how police and other first responders reacted during the most critical phases of the tragedy.

'Information gleaned from the actual conversations with Mateen and others lies at the core of understanding exactly how events unfolded and will provide critical insight into the propriety of the government's tactical response,' the suit said.

On Monday, the Federal Bureau of Investigation released a partial transcript of a 911 call made by Mateen from the club, and gave brief summaries of three other calls by the gunman.