Copyright Act

My son has worked on a final year engineering group project and completed it single handedly. There were no inputs from any of the other group members. Since it was a group project the project report carries the names of other 3 group members. The report also says that the original idea and concept is in my son's name. The report carries the signatures of all the group members and is endorsed by the head of the department. I would like to know if my son can keep the rights of the project idea to himself. Can the other group members claim rights to the project idea. If in future my son wishes to publish a paper on the same project, can the other group members claim their rights on the same. Please guide.