Mr Dickson had previously written to Malcolm McKibbin, Head of the NI Civil Service, to ask Mr Brimstone’s behaviour be fully investigated, after allegations emerged he had pressured a DUP Councillor to change her planned vote at a Housing Executive Board meeting.
Stewart Dickson MLA said: “While I welcome moves by DSD to start a preliminary investigation into Mr Brimstone’s conduct, this is only one aspect of the wider investigation needed.
“After these allegations came to light I immediately contacted Malcolm McKibbin and am glad to see he followed the matter up directly with the department. There have been some very serious allegations unearthed, ones that simply cannot be ignored.
“But it is not only the Minister’s special advisor that has questions to answer, but the Minister himself still has to fully justify his actions. A wider inquiry would ensure all issues are addressed and allow all the relevant information into the public domain.
“This incident has not only raised concerns over how DSD is led, but has also highlighted the weakness of the petition of concern. Designed to offer protection to minorities within the Assembly, the DUP have been able to use it to their advantage and to protect one of their own from further scrutiny. This must be reformed.
“While the general public will be glad to see some action taken to identify if any wrong-doing occurred, it must lead to a full and open investigation as we attempt to restore public faith in our political institutions.”