The robbery took place in an alleyway off Clarendon Street between 3am and 3.40am on Saturday 13 June 2015.
A man in his 40s was on his way home when it is reported that he was pushed in the chest and his blue holdall was stolen.
Investigating officer PC Anne Aylett said the victim was walking along the alleyway when he saw the suspect.
"The offender asked the victim if he lived nearby and tried to look inside the holdall he was carrying. When the victim turned to walk away the offender pushed him in the chest a couple of times, causing the victim to fall to the floor" said PC Aylett.
"The man then grabbed the holdall and ran off. The victim got up and gave chase but lost him and he was last seen in Folkestone Road."
The robber is described as being a foreign national, fair-skinned, about 25-years-old, of a thin build, 5ft 8ins to 5ft 9ins tall and was wearing a pair of navy blue jeans and a light blue fleece jacket.
Anyone with information is asked to phone Kent Police on 01843 222289 or Kent Crimestoppers anonymously on 0800 555111 quoting reference ZY/17739/15.
