I have a friend who was locked up for half a year on suspicion of gambling. The procuratorate does not have enough evidence to prosecute, and now the materials are detained in the public security bureau.
The Criminal Procedure Law stipulates that the detention time of a criminal suspect in a detention center shall not exceed 90 days. If the case is complicated and needs to be extended, it may be extended with the approval of the president of the county-level procuratorate, but the longest period shall not exceed 3 months; If the case is particularly complicated and needs to be extended, it may be extended with the approval of the competent leader of the Municipal Procuratorate, but the longest period shall not exceed 6 months.
According to your present situation, you have been detained for half a year, which is obviously beyond this time range. You can consult with a lawyer and the procuratorate.