TWO former housemates of murdered Indian student Nitin Garg have returned to India because of safety fears.

A housemate at Mr Garg's former home in the Melbourne suburb of Newport tsaid today that the parents of the two students demanded they leave Australia because of the outbreak of attacks against their countrymen.

"They were called home by their parents who were worried about what was happening here in Melbourne," the housemate, who did not want to be named, said.

The murder investigation has made little progress since Mr Garg was attacked and stabbed to death in a Footscray park last month as he made his way to work at fast food outlet Hungry Jack's.

But police appealed for a person they believe may have witnessed the attack on the 21 year-old.

Homicide squad Detective Inspector Steve Clark told reporters that new information had come to police in the last week from a young man understood to have seen a group of several men fighting in Cruickshank Park around the time Mr Garg was assaulted on January 2.

The potential witness is understood to be a regular patron of the Yarraville Hungry Jack's restaurant where Mr Garg worked.

"We haven't spoken to him, the information's come to us third hand," Det Insp Clark said.

"But clearly we are very, very keen to speak to him."

Police have not ruled out the possibility that the man, thought to be a Hungry Jack's employee observed by the witness, could have been Mr Garg.

"We don't know but clearly that's one possibility we're keen to explore," Det Insp Clark said.

He urged the witness to come forward.

"You may have the missing piece of the puzzle that we're looking for."