Mr Noel Smyth and Dunloe Ewart are trying to ascertain who bought 5.5 million of the property company's shares on Wednesday.

The 1.4 per cent stake, which would have cost in the region of $1.7 million, was bought from a single seller. The purchaser is understood to have been a UK company called Nortrust, though this company is thought to have been acting on behalf of the beneficial owner.

A further 1.5 million shares were traded on Tuesday and may have been purchased by the same purchaser. The shares have been languishing at around 31 cents as the chairman, Mr Smyth, and the property developer, Mr Liam Carroll, both of whom have stakes in Dunloe, have been unable to agree a direction for the company.

Mr Carroll has a stake of more than 27 per cent and Mr Smyth, along with his wife, has a 22.47 per cent stake. Mr Carroll has never discussed his views on the firm with Mr Smyth but has blocked a number of plans for Dunloe initiated by the chairman.

The stand-off between the two men has been ongoing for more than two years.

Mr Smyth, will now seek to establish who is behind the recent purchases of shares to ascertain whether they have any link to the stand-off.

If the shares were purchased by Mr Carroll, he would have to make an early declaration of the fact. For this reason, it is unlikely that he bought the shares through a UK firm.

Mr Dermot Desmond is thought to have taken up a small stake in Dunloe in recent times and may be seeking to increase that stake. A spokesperson for him could not be contacted last night.

Public companies can seek to have the holders of shares reveal the identity of their beneficial owner. However, if the shares are held by a trust, the mechanism does not work.

Mr Carroll has been sitting on a significant loss on his shareholding in Dunloe, as he bought his stake when the shares were trading at about 50 cents per share.

It is not clear why Mr Carroll has bought into the company. Mr Smyth told a recent annual general meeting that Mr Carroll had never discussed his investment with him.

"If you can imagine somebody spending €50 million to buy into your company and won't spend 10 cents on a phone call, that's what it is," he told shareholders.

The company recently voted to sell its portfolio of properties in Northern Ireland for a total of €141.5 million.

It owns properties in the Republic, notably a site on Sir John Rogerson's Quay, Dublin, opposite the IFSC, which is believed to be worth in the region of €50 million.