Iran Press/ America: Salvador Gonzalez is the highest-ranking official to have been detained in relation to the incident so far. He was arrested Sunday afternoon in Ciudad Juarez, the northern border town where the detention center is located.
Prosecutors have accused him of "direct involvement with behaviors resulting in the homicides and injuries suffered by victims".
Gonzalez did not immediately respond to requests for comment, though he has previously told Reuters he would cooperate with the investigation. The National Migration Institute (INM) declined to comment.
The agency's national head, Francisco Garduno, is also under investigation.
A handful of former INM agents, as well as an employee at a private security company contracted to work at the center, have been arrested as well.
Authorities say the fire broke out at the detention center in Ciudad Juarez in late March after one or more migrants set mattresses alight in protest.
As a result, 40 male migrants mostly from Central America, were killed and dozens injured in one of the deadliest migration incidents in recent memory.
According to Reuters, President Andres Manuel Lopez Obrador has said the migrants were unable to escape because the person holding the key to their locked cell was absent.
224
Read More:
Mexican officials find more than 3,000 migrants in 2 days
49 migrants dead, 58 injured in truck crash in south Mexico
