The FBI agent brother of a former NYPD cop jailed for allegedly hiring a hitman to kill her husband, has died by suicide, sources say.

Salvatore 'Sal' Cincinelli, 41, was found suffering at least one gunshot wound inside the Container Bar in Austin, Texas on July 17.

Cops flocked to the scene in response to a report of gunfire just before midnight and found him dead. Cincinelli was out with other FBI agents at the time.

The incident is being investigated as a suicide, according to the Austin Police Department.

He was the brother of NYPD cop Valerie Cincinelli, 35, who was arrested in May 2019, accused of orchestrating a plot to have her 'sugar daddy' boyfriend pay for a hitman to kill her estranged husband and her boyfriend's teenage daughter.

FBI agent Salvatore 'Sal' Cincinelli, 41, (right) died of a suspected suicide on July 17. He was the brother of ex-NYPD cop Valerie Cincinelli, 35, (left) who was arrested in May 2019, accused of plotting to have a hitman kill her estranged husband and her boyfriend's daughter

He was found suffering at least one gunshot wound inside the Container Bar in Austin, Texas during a night out with other FBI agents

Salvatore's death has left his imprisoned sister Valerie 'absolutely devastated'.

'She is absolutely devastated by the passing of her brother and best friend, and this is certainly adding to the stress of her current situation,' her defense lawyer James Kousouros said to the New York Post.

Salvatore Cincinelli was a former Wall Street trader who worked for big names like Bank of America and Global FX.

He switched career paths and joined the FBI in 2011 and headed financial crime probes in New York. He was later promoted to the FBI headquarters in Washington D.C.

He was interviewed by Reuters in 2012 after joining the FBI to investigate financial crimes.

'Some of my friends said, "Are you crazy? Have you lost your mind?"' he said at the time.

Cops flocked to the Container Bar in Austin, Texas (above) in response to a report of gunfire just before midnight on July 17 and found him suffering at least one gunshot wound. The incident is being investigated as a suicide, according to the Austin Police Department

An obituary posted online that has since been deleted said Cincinelli died on July 17. A funeral was held for him at St. Anthony's church in Oceanside last week and he was buried in the Holy Rood Cemetery in Westbury, Long Island.

He was the third person in his family to pursue a career in law enforcement.

His father Louis was a decorated officer with the NYPD before his retirement after 27 years of service, according to the New York Daily News.

The FBI is yet to comment on his death.

Valerie Cincinelli is currently detained without bail at Metropolitan Detention Center on charges of murder for hire and obstruction of justice.

Valerie Cincinelli was arrested in May 2019 for allegedly conspiring to have her 'sugar daddy' hire an assassin to kill her former spouse Isaiah Carvalho Jr. Both pictured above in 2017 with Cincinelli's daughter

John DiRubba, pictured in court in New York in June 2019, allegedly wore a wire as an FBI informant to help investigators look into his girlfriend Cincinelli after she mentioned the alleged plot

In the twisted alleged murder-for-hire plot the 35-year-old cop allegedly offered her 'sugar daddy' boyfriend John DiRubba – who paid for her car and bills - $7,000 to find a hitman.

She was conspiring to kill her husband Isaiah Carvalho as well as DiRubba’s 14-year-old daughter, it is claimed, as she was getting in the way of their relationship. Cincinelli has denied the charges.

She was arrested after NYPD launched a sting operation. DiRubba was allegedly involved in the sting as an FBI informant who was wearing a wire to help investigators.

She's due in court on Thursday in Nassau County for the latest hearing in her divorce from Isaiah Carvalho, who she's accused of plotting to kill.