In January 2021, the World Health Organization issued a statement confirming that issues exist with the RT-PCR test and the possibility of false positives. In fact below are some serious problems to take into account:

1. There can be large-scale test kit contamination, as both the US and the UK (and several African countries) discovered during the early phase of the pandemic.
2. There can be testing site or lab contamination, which has led to countless false positive results, school closures, nursing home quarantines, canceled sports events, and more.
3. The PCR test can react to other coronaviruses. According to lab examinations, this happens in about 1% to 3% of cases if only one target gene is tested, as is the case in many (but not all) labs and as the WHO itself has recommended to avoid ambiguous positive/negative test results.
4. The PCR test can detect non-infectious virus fragments weeks after an active infection, or from an infection of a contact person, as the US CDC confirmed.
5. The PCR test can detect viable virus in quantities too small to be infectious.

Full report by Swiss Policy Research below