Geraldine Larkin has resigned as the Chief Executive of the Irish Greyhound Board.
The semi-state agency announced news of her departure in a statement posted on their website this evening.
Larkin's tenure has been marked by criticism of the IGB's debt levels, the building of Limerick greyhound stadium, corporate governance at the agency and the controls in place for anti-doping in greyhounds.
Her position has been the subject of intense speculation within the greyhound community in recent weeks but news of her departure is still regarded as a major surprise.
In a statement, Larkin did however point to improvements in regulation during her time in charge and said: "I am particularly proud of the achievements in the area of regulation.
"Following on from the commissioning by the Board of a separate report into anti-doping and medication control were new regulatory measures to strengthen the anti-doping and medication controls within the industry.
"These included the publication of all adverse analytical findings and the prohibition of greyhounds from racing until a clear test is returned.
"Further measures included the establishment out of competition testing, publication of all decisions of the Control Committee and the Control Appeal Committee, testing informed by intelligence and links to other sporting bodies."
In a separate development; the Greyhound Board of Great Britain has issued a directive that no Irish dog be allowed run in the UK without first being tested clear of drugs.
Irish greyhounds have tested positive for an array of drugs both here and in the UK in the last two years including the Class A drug Cocaine and the drug used to treat male erectile dysfunction - Viagra.
