Activist investor Carl Icahn filed a lawsuit on Monday against AmTrust Financial Services Inc and the family that controls the company, accusing them of trying to take the insurer private at the wrong time and at the wrong price.

The lawsuit filed in the Court of Delaware accuses Karfunkel-Zyskind family of engaging in a transaction which will transfer "huge amounts of value" belonging to the company’s public stockholders to the controlling family.

Earlier on Monday Czech-based Arca Capital, which own 2.4 percent of total outstanding shares of AmTrust, said it plans to work with Carl Icahn and other minority shareholders in opposing the proposed privatization transaction.

Icahn had disclosed a 9.38 percent stake in AmTrust on May 17.

On March 1, AmTrust said it would be acquired in a $2.7 billion deal by a group of shareholders including its founding family, chief executive officer and private equity funds - a move that Icahn has strongly opposed.