Elan has gathered a dossier of evidence on what it claims are calculated efforts by hedge funds to drive down the company's share price.

"We are aware of specific circumstances where certain individual groups have taken advantage of the decline in the stock subsequent to erroneous reports that sometimes appear in the press," said Elan chairman Dr Garo Armen.

Suggesting that press reports may have been deliberately planted by hedge funds in order to move Elan shares in a particular direction, Dr Armen said the behaviour of hedge funds was "potentially an issue" in the stock's performance.

"I'm certain that among them, there are those who are betting on their fortunes to be dramatically opposite to the fortunes of Elan," Dr Armen added.

Dr Armen declined to comment on where he might present evidence on the matter.