Yusupha Sallah, 32, and his toddler Yunus were attacked on a bridge by a gang who racially abused him and threatened to kill his son.
Depite a major appeal the case appeared to be going cold as police admitted that witnesses were too frightened to speak out. However, the investigation has moved forward according to the head of the police hate crimes unit Thomas Bull.
"We have received some new information. It involves what these people have done and what role they had. That is what we are trying to piece together now," Bull told local newspaper Sydsvenskan.
Sallah, who only recently moved to Sweden from Denmark due to rules over residency permits, was left shaken by the attack. He was beaten up and almost thrown off a bridge while his infant son was also hurt after a gang kicked a toy out of his hand.
"I asked them why did they do that to a small baby. He answered me 'you fucking black man, you better pick up your son and go or I'm going to kill the both of you,'" Sallah told SVT in a recent interview.
A flurry of new tips were given to the police after the incident featured on the Swedish crime programme Efterlyst ("Wanted") last week.
The victim was able to identify some of the faces who attacked him with the police saying they are confident the case will be solved.
It's understood that there is some video footage of the attack which police are anxious to see. Bull said people in the area may be afraid of reprisal attacks and also may be unwilling to speak to the authorities as they have a prior criminal record.
"It's something we see in other cases like shootings and the like. They will simply not talk to the police," he said.
One witness told Sydsvenskan that the gang who carried out the attack still walk regularly across the bridge.
"They often walk around here and act as if nothing has happened," said the witness.
Bull said he is optimistic the case, which generated headlines around Sweden, will be solved but added that it may take a while.
"The investigation is moving forward. We are in a delicate position on the case just now but we hope we are on the right track."
The victim of the attack is currently living with his son under police protection.