Global financial turmoil saw the Australian RMBS market "effectively shut for a couple of months", the Australian Office of Financial Management confirmed on Friday.Michael Bath, the AOFM's director of financial risk, told the Senate Economics Committee on Friday that "things are only just beginning to pick up" in the RMBS market.His comments closely match those made earlier in the day by APRA chairman John Laker. But the AOFM executive appeared to have reached a more optimistic judgement about recent improvements in the broader markets."Through the back half of July, August and September, debt capital markets in the credit space more generally have been effectively shut," he said. "But they have reopened in recent weeks.""Two $1.5 billion RMBS issues by the NAB and Westpac in the past month had reopened the market," he said.