Among the issues the RAIB said it would consider are the actions of those involved and the arrangements in place to manage and control the risks associated with passengers getting on and off Elizabeth line trains.
A TfL spokesperson said the operator of the service, MTR-Elizabeth line, is currently carrying out a thorough investigation into the incident which happened just after midnight.
The spokesperson said: “We will always strive to learn from incidents and improve operational safety.
“MTR-Elizabeth line is fully co-operating with the RAIB to establish the root cause of this incident to determine what steps they can take to avoid any further events of this nature and to share learnings with the industry.
“While serious injuries on our network are rare, we are undertaking a huge range of work aimed eradicating such incidents and making travelling even safer for everyone.”
In June 2023 the RAIB investigated after two people were dragged along London Underground platforms by trains when their coats got stuck in the train doors.
The incidents happened at Archway and Chalk Farm stations on the Northern line.
The passenger at Archway was seriously injured after being dragged along the platform for about 2m (6.5ft) when their coat became trapped in the doors of a northbound Northern line train.