Mrs Richter went around the neighbouring houses asking if they had seen it but no one knew anything.
She then went to the police but they were also unable to find out what happened.
The missing walker just made life more difficult for Justin, who was nursing a broken leg.
"The nature of the disease made breaking bones very easy for him, all he did was twist his leg and it broke."
Mrs Richter was now too nervous to let him out of his chair.
"The last thing poor Justin would want would be another broken bone and the walker is what gives him that extra support when he needs it most."
The walker was given to them by the hospital and she hoped people understood how much her son needed it, to live every day as normally as possible.
"He needs his walker, without it he is stuck in his wheelchair and misses out on exercise and playtime".
Mrs Richter was offering a reward to anyone who had information about the missing bright metallic blue walker.
"I just hope it has not been thrown over a bank or down a ditch somewhere, as it is something my son really needs," she said.
"It is not something you just take for a joy ride."
If you know anything about its whereabouts please contact Marina Richter on 06 874 6777.