Prosecutors conducting a supplementary investigation into last year's Itaewon crowd crush raided the Seoul Metropolitan Police Agency on Monday.

The Seoul Western District Prosecutors' Office sent investigators to the Seoul police agency's emergency situation room in the morning to seize data on transmitted and received messages.

The prosecution suspects that two Itaewon substation patrol chiefs either drew up or fraudulently revised reports on incoming emergency calls ahead of the fatal crush.

They are accused of falsely claiming in written documents that they had counseled the callers and arrived at the scene of the tragedy.

In January, a police special investigation team referred their cases to the prosecution for indictment without pretrial detention on charges of causing deaths and injuries due to gross and occupational negligence.