THE son of former first minister Peter Robinson and a former Nama official are to be called before a Stormont inquiry over suggestions they helped prevent the agency from moving against certain debtors. PR man Gareth Robinson and Ronnie Hanna have been sent letters inviting them to attend the finance committee probe into Nama's £1bn northern portfolio deal. Accountant David Gray, a partner in Belfast firm McClure Watters, has also been asked to appear before the inquiry. It comes after a BBC Spotlight programme revealed covert footage that suggested Mr Hanna "prevented [...]