Investigators say the pair used high-pressure sales techniques

Investigators allege Paul Gunter, 58, and daughter Zibiah, 25, from Florida, sold fake shares in 50 dormant firms.

The pair have been charged with money laundering, mail fraud and securities fraud, US officials said.

If found guilty, they could face up to 25 years in prison and a fine. They are due to appear in a Florida court later.

The BBC's Andy Gallacher, in Miami, says it is thought the Gunters hijacked the identities of the dormant, publicly traded companies and used high-pressure sales techniques to sell worthless shares to British investors.

They are believed to have started the alleged scam in early 2005, US investigators said.

Deputy chief inspector Robert Wishart, head of the money laundering unit at City of London Police, said the arrests were part of an ongoing investigation into a "mass-marketing crime scam known as boiler room fraud".

In a statement released by the US Immigration and Customs Enforcement (ICE) agency, he added: "Thousands of British people have fallen victim to this crime - in this inquiry alone, we estimate that around 15,000 mostly elderly people have lost money."

He said the arrests demonstrated the power of international collaboration to bring to justice those suspected of crimes, even if based overseas.