New York state is launching an investigation into claims that the Kushner Cos. harassed rent-stabilized tenants in an apartment building it was converting to condos in Williamsburg.

The allegations surfaced in a lawsuit brought by tenants of the 338-unit Austin Nichols House.

The lawsuit was filed Monday after an investigation by the Associated Press found that more than 250 rent-stabilized apartments were sold or left vacant as the company converted them to luxury condos.

Tenants claim the construction occurred around the clock, with noise so loud, they could not tolerate being inside.

Worse, they claim that dust filling their building contained cancer-causing compounds.

The company is no longer run by Jared Kushner, the president’s son-in-law.

Christine Taylor, a spokesman for the Kushner Cos., said the lawsuit is “totally without merit” and all complaints were addressed before construction was completed in 2017.

​”​The residents of Austin Nichols House were fully informed about the planned renovation and all work was completed under the full supervision by the New York City Department of Buildings and other regulatory agencies, with full permits and with no violations for these claims​,” she said​.​ “​Tenants were never pressured to leave their apartments and the market-rate rent stabilization was – and continues to be – complied with under applicable rent guidelines.​”