(Yicai Global) Sept. 11 -- Ziroom Shunguo Asset Management, whose long-term rentals platform is under fire after a tenant died from exposure to formaldehyde, has delisted 20,603 first-time rentals for air testing and treatments.

The Beijing-based firm took down the newly-remodeled listings, spanning nine cities, on Sept. 1 and has been working with 62 agencies approved to carry out China Metrology Accreditation tests, state-backed news outlet The Paper reported today, citing a company statement. Ziroom is testing as many as 1,147 properties a day, the report added.

The company, which is owned by leasing giant Lianjia, or Homelink, is offering air treatments to those who are still waiting for their tests, and is working with another 71 companies to treat the air in 2,211 homes a day, it added. It has also partnered Chinese tech giant Xiaomi to provide air purifiers to tenants.

Tencent-backed Ziroom has been fighting to ensure air quality at its home after an Alibaba employee surnamed Wang died of acute leukemia in July after living in a Ziroom flat for six months. After he died, his family carried out tests on the apartment and found higher-than-normal levels of formaldehyde. Wang's wife is suing the company through a Hangzhou court over his death and a hearing is scheduled for Sept. 27.

"Some customers suffered health problems after living in our rented homes and we're working hard to deal with the issue," Chief Executive Xiong Lin said in a televised interview with Yicai Global, his first since news broke of Wang's death.

"We're committed to ensuring that all Ziroom rentals from now must be proved safe via a CMA inspection," he added, saying that reports would be published online and no units would be available until given the all-clear. The firm anticipates getting properties back on to the market on Sept. 24, according to The Paper's report.

Any tenants who began renting apartments after June 1, 2018 may apply for a free air quality test if they have any concerns, the firm added. If any irregularities are found, the company will allow the tenant to cancel their contract with a full refund, receive a free purification treatment, or be given an air purifier to use without charge for 90 days.

Editor: James Boynton