The Central Bank has issued its fourth warning about the activities of Millennium Financial Ltd, an international boiler-room operation that has been targeting Irish investors.

The Central Bank's notice comes just two weeks after the Securities and Exchange Commission (SEC) in the United States obtained a temporary restraining order in the New York courts against Millennium, which specialised in selling shares in companies that it claims are about to join the stock market. It tells investors that the shares will jump in value either just before or after flotation.

Irish investors are among the 150 people defrauded of more than $2 million (€2.12 million) by Millennium. The company "cold called" prospective investors in 20 countries but the majority of those defrauded were in the Republic and Britain.

"The fact that these firms are still trying out the Irish market indicates they're obviously having a certain amount of success, otherwise I guess they wouldn't be pursuing it," said a Central Bank spokesman.

"Our advice always is that you should not deal with a firm unless you're satisfied of its bona fides. If you are not sure it is authorised, you should contact the Central Bank and we will put you straight."

The Central Bank already issued warnings about Millennium in March 2000, October 2000 and February 2002.

Millennium, which the Bank said operated out of Uruguay, Brazil, Switzerland, Singapore and Mexico, is just one of four firms that are the subject of the warnings issued by the Central Bank in newspapers today. The other firms are: Clover International Advisors, operating from the US; International Consortium Growth Holdings, operating from the Bahamas and the US; and Lloyds and Associates, operating out of Spain.

It is the second time the Central Bank has issued a warning about International Consortium Growth Holdings, the last one was issued in March 2001.

The Central Bank spokesman said it had informed the SEC that it was issuing a warning notice about Millennium continuing to offer unsolicited investments to Irish investors.

The Central Bank confirmed several weeks ago that it had received more than 80 complaints about calls from Millennium offering unsolicited investments. It said it believed that only around half a dozen people had lost money, but added that some individuals who were taken in might be reluctant to come forward.

The SEC said last night that its action was more concerned with the content of Millennium's unsolicited offer, rather than the fact that it was operating as an unauthorised entity, which concerns the Irish Central Bank.

"The New York action is based on what they are telling people and not simply the fact that they are calling people," Mr Paul Berger of the division of enforcement at the SEC said.