Police say that there are "deeply concerned" about Mikaeel Kular but stressed that it remains a missing person inquiry. Mikaeel has not been seen for 40 hours since he was put to bed on Wednesday night.
Police said they have checked CCTV from the local area but that nothing significant has been found so far and are following many lines of inquiry.
More than 150 calls have been made to the hotline for those with information.
The number is 0300 200 0200.
You can also contact Crimestoppers anonymously on 0800 555 111.
Read more: Latest updates on the search
A timeline of events surrounding the disappearance of three-year-old Mikaeel Kular.
What tools and techniques will police be deploying in their effort to reunite Edinburgh toddler Mikaeel Kular with his family?
Hundreds of people have gathered to join the search for a missing three-year-old boy who was last seen on Wednesday night.