Witness Ricardo Héctor Coquet has testified in court that records were kept of the around 4,700 prisoners who passed through the ESMA.
He stated that three microfilm copies of the archives were made before the originals were destroyed: one for the now late Rubén Chamorro, head of the ESMA, one for dictator Emilio Eduardo Massera, and the third for Jorge "el Tigre" Acosta, who is currently standing trial.
Coquet further described his tasks of falsifying documents for the task forces who carried out the abductions.
This testimony certainly seems to fit with that of Victor Basterra who photographed in the ESMA. I wonder if any of those microfilms have survived. While I don't think we are really lacking in evidence to convict the perpetrators, the contents might clarify what happened to some of the disappeared.
Los archivos del Tigre Acosta (Projecto Desaparecidos)
Entrevista a Ricardo Hector Coquet, sobreviviente de la ESMA (radio nacional - audio interview, Spanish)
"Hay microfilms de 4700 secuestrados" (Pagina/12)