According to a report in the Wall Street Journal, Theranos, a beleaguered, multi-billion-dollar startup developing blood testing technology, is presently facing investigation by two federal agencies.

Former employees’ complaints have sparked the two investigations. One investigation is by the Food and Drug Administration, and the Centers for Medicare and Medicaid Services (CMS) is conducting the other one. As per the WSJ, the complaints gave rise to concerns over breached research protocols and severe accuracy issues with the company’s blood tests.

Earlier this year, Theranos got prominence and drew skepticism with claims that it could conduct a multitude of medical tests using only a few blood drops. While earlier media reports have also triggered concerns over the accuracy of the fingerprick-based tests, the latest report has outlined concerns related to the only blood test that has FDA approval, a herpes test.

While speaking to WSJ, a spokeswoman for Theranos, Brooke Buchanan, said that the company hasn’t seen “a copy of any alleged complaint, so we have no basis to evaluate what is in it or even if a complaint has been filed”.

An ex-employee filed a complaint with the CMS in September saying that Theranos managers knew about inaccuracies with the company’s testing devices, known as Edison machines, since 2013. The employee said that the Edison devices would come out with wildly distinct results for the same patient.

The ex-employee said that for instance, in a thyroid hormone test, the Edison’s results would swing between displaying that a patient had hypothyroidism (quite little hormone) to hyperthyroidism (quite much hormone).