actually another thought . The checks could be done about 6 moths or so after application lodged to give less chance of having to do them again. I imagine theydo not even start to process applications for 6 months or so anyway and one can forward further info at any stage . I assume you would need toknow where to get medical done and only they can tell you that ?Not true. Sometimes if it's only within a few weeks of expiry, they'll let it pass (I know of this happening to a personal friend), but more often than not from what I read on here, they request new ones.
Immigration do warn everyone that police checks and medicals are only valid for 12 months for immigration purposes and that it's best to wait until contacted, so I assume people that do them without being requested know the risk and are willing to take it in hopes of a speedier approval by having a decision ready application. This is what I did and I was prepared to pay the cost to get them done again if necessary.