David Koch Replaces Mayor Michael Bloomberg as Manhattan's Wealthiest Man Updated September 23, 2010 6:57am

Billionaire David Koch has ousted Mayor Michael Bloomberg as Manhattan's wealthiest man. (Bryan Bedder/Getty Images)

By Jennifer Glickel

DNAinfo Reporter/Producer

MANHATTAN — Oil heir, philanthropist, and alleged Tea Party funder David Koch has stolen the title of Manhattan's wealthiest billionaire from New York City's Mayor Michael Bloomberg.

Koch and his brother, Charles, share the number five spot on "Forbes" magazine's list of the 400 Richest Americans, with a combined wealth of $21.5 billion.

Mayor Bloomberg is no longer New York's richest man. (Getty Images)

Bloomberg's ranking fell to 10th place, down from his former spot as eighth richest man in America, with a piggy bank worth $18 billion.

Charles, who lives in Witchita, KS, and David Koch were recently revealed in a New Yorker article to be the bankrollers of the Tea Party movement.

Both deny their involvement with the Tea Party, but the magazine reports that they have given money to extremely conservative groups that are against social security and do not believe in global warming.