Over the past number of years, Deutsche Bank, the German banking giant, has quietly built an Irish property empire operating through an investment subsidiary called DWS. In the last 18 months alone, DWS has ploughed more than half a billion alone into Dublin property bringing its total Irish spend to more than €700 million. Its assets include 700 buy-to-lets, 1,000 rooms in student accommodation and the Westend Retail Park in Blanchardstown in west Dublin. One of the tenants there is Heatons, the department store chain owned by the British retail magnate Mike Ashley. Now, it has emerged that there is…