The incident happened on Saturday, August 25, at approximately 10.23pm.
The victim – David Edward Lovett, from Worthing – died on the platform despite the best efforts of paramedics.
His son described the theft as the ‘lowest of the low’ and ‘absolutely disgusting’. Read the full interview here.
In a statement, British Transport Police said: “Officers would like to speak to the man pictured in the images because they believe he may have information which could help officers investigate.
“If you recognise this man or have any information which could help our investigation, call 0800 40 50 40 or text 61016, quoting 681 of 25/08/18.
“Alternatively, if you prefer, you can ring Crimestoppers anonymously on 0800 555 111.”