A horrified mum has said she now fears for her son's safety after he was approached by a strange man who asked to take pictures of him before chasing him in Eltham.

Vicki Todd, from Sidcup, told News Shopper her 13-year-old son Kai had visited McDonald's with two of his friends yesterday when a man allegedly approached the group of boys and began to ask them questions.

She claims the boys ignored his questioning at first before he allegedly asked them to send him photos of themselves and if he could take photos of them himself.

She also claims her son heard the man make noises which sounded "sexual" as he spoke to them.

Mrs Todd said that after leaving the restaurant, her son and his friends witnessed the man allegedly running towards them, to which they fled.

"My son and one of his friends ran into Lidl while his other friend hopped onto a bus.

"The man hopped on the bus but the other child got off through the front door then," she said.

Mrs Todd said her son is still shaken up after the encounter.

She said that when she took Kai to her local police station to make a statement, she was disappointed to hear that they could only file an intelligence report and would not be making any follow-ups as no crime was committed.

"I am concerned that there is already a lot of crime in the area. Surely a proactive approach would help.

"Without any investigative work, how can any problems be dealt with?" she said.

Bexley police has been contacted for a comment.