On 21 May 2021, the Linyi Municipal Procuratorate informed Ding Jiaxi's legal counsel that it has sent his case back to the Linyi Municipal Public Security Bureau for a second round of supplementary investigation. Under the Criminal Procedure Law, only two rounds of supplementary investigation are permitted. Once the supplementary investigation has concluded and the case is sent back to the Procuratorate, the Procuratorate must then decide whether or not to prosecute within a month. The Procuratorate may extend this deadline by another 15 days if a case is deemed "major or complicated" or if the sentence might exceed one year of imprisonment.

Earlier on 19 May 2021, Ding Jiaxi was allowed another video call with his legal counsel. Ding Jiaxi told his lawyer that detainees are permitted to partake in outdoor activities for less than 30 minutes a day and that their masks are changed only once every three weeks. Due to the low quality of dental hygiene provided by the detention centre, the condition of the human rights defender's teeth is deteriorating. Ding Jiaxi also said his eyesight has deteriorated, and he has still not been given any paper or pen to write with by authorities.