Police have named the woman and child killed by a speeding train at Slough station as Rubina and Amaar Khan, a mother and son.
Rubina, 46, and 10-year-old Amaar fell on to the tracks and died in what police say were suspicious circumstances.
It is possible the incident on Tuesday morning was a murder-suicide. British Transport Police did not rule out that the pair may have been pushed.
British Transport Police said: "Although we have yet to formally identify the deceased following yesterday's incident at Slough railway station, we can confirm we strongly believe them to be Rubina Khan, 46, and her son Amaar Khan, 10.
"Specialist officers are currently providing support to the family, and we ask that they be left to grieve and come to terms with what has happened."
The Khans' deaths at Slough station in Berkshire disrupted train services on four lines, including to and from London, while police forensic investigators combed the scene.