The manslaughter complaint was lodged last Friday by the family of a 19-year-old man from the Paris suburb of Étampes who was killed on the platform as he waited for the train which was destined for Limoges.
Under French law, such complaints allow investigators to pursue a wide-ranging probe that does not target any particular individual or company.
During a ceremony held in tribute to the victims of the crash, a friend of the victim said the man, who is originally from Guadeloupe, came to France in 2011 for his studies and had lived with his 23-year-old brother.
The news emerged one day after the death toll from the crash rose from six to seven, when a 67-year-old woman succumbed to her injuries.
The woman had been in a critical condition since the crash, media reports said, and was being treated in a hospital in the region.
Of the other six who were confirmed dead on the day of the disaster, two were passengers on the train and four were people who had been standing on the platform. It is not clear whether the seventh victim had been on the train or the platform when the accident occurred.
French rail operator SNCF blamed the accident on a connecting bar that had come loose at a rail switchpoint.
Four people are still in hospital following the crash, according to local police.