Brooklyn’s Barclays Center is too cheap to pay for adequate security, a former manager claims in a lawsuit.

Weapons have been snuck into the arena via faulty metal detectors and inadequate security screenings, and the facility has too few guards, alleges Steven Samedi, 32.

The arena is home to the Brooklyn Nets and the New York Islanders.

Barclays bosses “refused multiple requests by Barclays security for resources, claiming that [they] do not have the budget for even the most basic security measures,” according to the Brooklyn Federal Court claim.

Barclays, which holds 19,000 people for concerts, 17,732 for basketball and 15,795 for hockey, hosts about 250 events a year and has a “legal obligation to ensure public safety,” especially “in an era where terrorism and mass shootings are all too common,” according to the lawsuit.

The venue had just 139 security guards at the time of Samedi’s 2018 dismissal, when it should have had 250 to 300, he claims.

And when something did go wrong — such as fans trampling the “meager” security and getting weapons inside the Sept. 1, 2015 Power 105.1 Powerhouse concert, or UFC fighter Conor McGregor’s April 5, 2018 meltdown on the loading dock, in which he and his entourage attacked a rival’s bus — no security staff was disciplined, Samedi charges.

The arena is run by Brooklyn Events Center and Anschutz Entertainment Group, two entities which also operate Long Island’s Nassau Coliseum. AEG runs or owns 150 venues around the world.

Samedi was fired after higher-ups blamed him for the April 21, 2018 incident between rappers Tekashi69 and Casanova during the Adrien Broner-Jesse Vargas boxing match.

Management “didn’t want to pay more than $20,000” for security, despite Samedi’s warnings about Tekashi’s gang affiliation, the former security assistant manager said in court papers.

No one was hurt when a gun was fired. A Tekashi associate was later arrested for the shooting. But it was Samedi who took the blame, he charges.

Barclays bosses allegedly suggested Samedi, a black, tattooed Brooklyn native, “had somehow orchestrated the confrontation between Casanova and Tekashi69” and accused him of failing to follow procedures – though they never outlined which rules he had allegedly broken, he said. He said the accusations were racially charged.

Samedi’s claims are “patently false,” and the venue ensures security protocols “exceed all standards,” an arena spokeswoman said in a statement, adding that Samedi’s firing “was both lawful and appropriate.”