Thousands of migrant children stopped while trying to enter the United States America, say they were sexually abused in custody by US border authorities.

Reports indicate that the children came alone in the US where they were taken into custody, and now the Democrats in Congress internal documents say thousands of them made allegations they were sexually assaulted, where they were being held by US government agency.

From 2014 until last year, a total of 4556 claims of migrant children who were sexually assaulted by officials in the US were reported, and 1303 of them were deemed credible enough to be sent to investigators.

A total of 178 claims were against a member of the detention staff.

Reports also indicate that the man in charge of the program was defensive before the congressional hearing.