(Yicai Global) Sept. 13 -- Authorities in Shenzhen have found that a third-party air tester hired by rental agency Ziroom Shunguo Asset Management, which is facing public backlash after the death of one of its tenants, has been operating without a license.

The Shenzhen Market and Quality Supervision Commission and Academy of Metrology & Quality Inspection conducted an onsite investigation on Sept. 11 based on speculation from tenants that air testing and treatment companies hired by Ziroom were not suitable qualified, an Yicai Global reporter discovered. The results showed that the firm in question, Shenzhen Sikaixi Environment Protection, did not have the required China Metrology Accreditation certification.

Tencent-backed Ziroom announced this week that it was delisting 20,603 first-time rentals from its platform for air testing and treatment, just weeks after a tenant died of leukemia after being exposed to excess levels of formaldehyde in a home leased via Ziroom. His wife is currently suing the firm and has a court hearing in Hangzhou scheduled for Sept. 27.

The Beijing-based firm hired 62 testing agencies and 71 treatment companies in nine cities to tend to the newly-remodeled properties, it said in the announcement. It planned to test over 1,100 properties daily and treat 2,211 a day, and claimed the firms were all CMA licensed.

Another Ziroom tenant, surnamed Lu, said that she has been suffering with stinging eyes, rhinitis, allergies and other symptoms since October last year, but Sikaixi gave the house the all clear after an air test. The results report presented to Lu did bear the company seal, but she noticed there was no CMA logo and has always doubted the report's authenticity.

Editor: James Boynton