Four partners in the Belfast office of international accountancy firm KPMG have been arrested on suspicion of tax evasion.
The senior management figures are now on “administrative leave” after an investigation was launched by HM Revenue and Customs officers.
HMRC officers detained the men on a visit to the Belfast city centre office on Wednesday.
It is understood the partners are Jon D’Arcy, Eamonn Donaghy, Arthur O’Brien and Paul Hollway.
A KPMG spokesman said the company was “co-operating” with the HMRC investigation.
“It is important to emphasise that we do not have any indication that this investigation relates to the business of KPMG or the business of our clients,” he added.
“Pending further information and enquiry, we can confirm that four partners in our Belfast office are on administrative leave.
“As the matter is on-going, KPMG is not in a position to make any further comment at this stage.”
Away from KPMG, the four men set up their own property investment company in 2005.
A spokesman for HMRC said: “HMRC officers arrested four individuals from Northern Ireland yesterday in connection with suspected tax evasion. We can’t comment further.”
Mr Donaghy is KPMG’s head of tax in Belfast and has been heavily involved in the campaign to have corporation tax powers devolved to the Northern Ireland Executive as chair of the group Grow NI.
He was named Business Personality of the Year in the 2014 UTV Business Eye Awards, largely in recognition of his role in the campaign.
Mr Hollway is head of corporate finance in Ireland.
Aside from their main roles, the four men are directors in a property investment company called JEAP Ltd which is understood to have made heavy losses in the 2008 property market crash.
It is not clear if that forms part of the HMRC investigation.