In a statement, the Ministry of the Interior (MAI) said that the investigation was aimed at "investigating the circumstances of the said flight and possible disciplinary responsibilities of members of the Foreigners and Borders Service (SEF) and the Public Security Police (PSP).
"The Minister of the Interior ordered the General Inspectorate of the Internal Administration (IGAI) to open an enquiry into the facts relating to the flight of 17 foreign nationals who were staying at Atalaia headquarters, from the Infantry Regiment No. 1 of the Tavira Detachment", reads the note.
The 17 migrants were part of a group of 28 who landed on the Deserta island, in Faro, and who were then, by court order, placed in the custody of SEF until they were removed from Portugal.
The group also included three women, one pregnant, and a minor, but only the 24 men in the group were settled in the barracks of Tavira, SEF said in a statement.
The same source added that "police authorities have already located two citizens".
As well as the 24 men installed in Tavira's barracks, the three women who were part of the group "were installed in the Santo António Housing Unit in Oporto", while the "minor was handed over to the Faro Family and Minors Court", SEF also explained.