I thought anyone who passes through London needing a visa is of high interest?If he is not of interest at london then he will be at malta at some point he is going to be investigated.Most likely from Jamaica side then?I think all of the prooving has to be done in country of residence-once you have the document you need you're good to go.I think its the prooving that is the hard part.The situation I know personally of they wanted to know the ins and out of EVERYTHING.