Business owners in Queens are suing the city and the NYPD for $300 million, saying they’ve been strong-armed and harassed into not cooperating with a police investigation into a sweeping karaoke-bar bribery scandal.

Owners of Flushing bars 360 Lounge, Forbidden City and Home Run KTV accuse NYPD Commissioner Bill Bratton of ordering the crackdown in the Asian community to “intimidate” witnesses during a two-year probe of more than 20 officers from the 109th Precinct, the Brooklyn federal court complaint says.

In December, NYPD Lt. Robert Sung and Detective Yatyu Yam were arrested for allegedly taking bribes from karaoke bar owners in exchange for tipoffs of impending raids and intervening in customer arrests.

The suit claims Bratton’s edict stemmed from being “unhappy about the karaoke bar protection scandal impact upon his legacy” — so he met with Internal Affairs Bureau Deputy Commissioner Joseph Reznick, Assistant Chief of Queens North Diana Pizzuti and former 109th Precinct commanding officer Thomas Conforti and told them to “handle” it.

Since late 2014, the club owners say, they’ve been subjected to unlawful “business inspections” and a beefed-up presence of cops at their establishments, while their customers have been wrongfully stopped and frisked and even arrested for no reason, the complaint says.

Under the guise of “inspections,” officers were ordered to go to the Japanese-style bars, where they “would remain inside for hours on end,” causing customers to leave.

Wang Zheng, owner of Home Run KTV, alleges Bratton and the city sought to have the club declared a public nuisance and stripped of its liquor license, court papers say.

It was also the site of the arrests of 18 members of the Asian community in April 2015, after Bratton and other top police brass allegedly claimed that three drug deals took place there, the suit says.

The plaintiffs claim to have a January cellphone recording in which William Seeger, an IAB lieutenant who worked on the investigation, tells another IAB official that Conforti has a “hit list” and that Pizzuti is “corrupt,” according to the lawsuit.

But they say video evidence of the illegal searches was seized.

“The police can’t police themselves,” said Eric Sanders, an attorney for the plaintiffs. “What should’ve happened is this really should’ve been referred to the Department of Investigation. There’s no way police should’ve been handling this investigation.”

The suit also accuses Bratton of employing the same shady tactics before — during the “Dirty 30” scandal in Harlem in the 1990s that resulted in the arrest of 33 corrupt cops.

The lawsuit, which alleges racial discrimination and civil rights violations, say the karaoke-bar scandal probe focused on 23 other NYPD officers, including two captains, three lieutenants, three sergeants and three detectives.

The NYPD didn’t return messages seeking comment.

“The complaint will be reviewed,” said a city Law Department spokesman.