Adviser admits he 'should have dug deeper' as suggested Arlene Foster wrote blank cheque for scheme

A former special adviser to DUP leader Arlene Foster has said he "should have dug deeper" into the details of the ill-fated renewable heat incentive (RHI) scheme.

The chairman of a public inquiry into Stormont's botched green energy scheme, Sir Patrick Coghlin, said it would have been "common sense" for Dr Andrew Crawford to have familiarised himself with a report on the detail of the scheme.