SAN FRANCISCO (AP) — San Francisco officials are investigating Twitter after six former employees allege that owner Elon Musk’s leadership team broke laws by turning the company’s headquarters into a “Twitter Hotel” for workers who were pushed to stay up late to transform the social media platform.

The San Francisco Department of Building Inspection said Friday that it has opened a new complaint and will be conducting an investigation into the new allegations.

The San Francisco Chronicle earlier reported on the city’s latest investigation into the company that Musk took over late last year.

That’s after the ex-employees, including a former vice president of real estate, alleged in a lawsuit filed in a federal court in Delaware that Twitter didn’t pay them promised severance. Twitter is seeking to have the case dismissed.

The ex-workers also allege that Musk’s team ordered numerous changes to the company’s headquarters in a 1930s Art Deco building in downtown San Francisco that violated building codes. Those changes included disabling lights and adding locks that wouldn’t open during an emergency, according to the lawsuit.

One of the plaintiffs is Tracy Hawkins, Twitter’s former vice president of real estate and workplace, who was responsible for managing the company’s physical offices and leases. The lawsuit says Hawkins wasn’t initially opposed to Musk’s takeover but “was forced to resign when Elon Musk and his transition team insisted that she violate her professional ethics by causing Twitter to intentionally breach its leases and other contracts.” The lawsuit claims Musk refused to pay rent on the building.

This is not the first time San Francisco officials have tussled with Musk, who bought Twitter for $44 billion in October and gutted much of its workforce as he converted a part of the company’s headquarters into bedrooms.

Earlier this year, San Francisco building inspectors gave Twitter’s construction contractor two weeks to submit a corrected building use permit if the company wanted to keep using two conference rooms as bedrooms.

The city launched an investigation in December after Forbes reported on the beds, prompting Musk to lash out at San Francisco Mayor London Breed, even though there is no evidence she was involved in the inspection.