Can a non-resident UK national open a sipp in the UK?

I've been living in Australia for over 10 years, on home duties. I've paid (and am only one payment from completing) enough NI contributions for UK pension eligibility. My enquiry is back-to-front! I would like to build a pension fund in the UK while based overseas. I have accessible funds in the UK and am at a loss as to how to best put them to work there. I've wondering about starting a sipp. As a non-resident UK national, can I open a UK sipp with funds in a UK bank account? Would I do better move the funds offshore (eg Isle of Man of Channel Islands)? I do not anticipate drawing a pension for another 15 years. Any pension investment suggestions?