Glanbia has declined to comment on the departure of Bill Carroll from its board of directors.

Mr Carroll had been at the centre of a Department of Agriculture investigation into milk quota infringements.

He is alleged to have sold close to €300,000 of milk to Glanbia from his Co Tipperary farm using the quota attached to Clongowes Wood College farm in Co Kildare.

Under milk quota arrangements, farmers are not permitted to supply milk that has not been produced by their own cows on their holdings. They are also liable to receive substantial fines if they supply more than their quota.

On completion of the department's investigation, Minister for Agriculture Simon Coveney said corrective action had been taken, and that on advice from the Chief State Solicitor's Office no prosecution was warranted. Mr Coveney also noted the milk deliveries concerned had been reallocated and any fines arising were to be paid in full.

Mr Carroll was one of 14 farmer non-executive directors of Glanbia Plc. The company announced his departure in a note to the Irish Stock Exchange last week.

It said it had been "informed that Mr Bill Carroll has today resigned as a member of the board of Glanbia Co-operative Society Limited. As a consequence, the company confirms that he has automatically ceased to be a director of Glanbia plc."