Image caption Ray Nagin's indictment has been long expected

Former New Orleans Mayor Ray Nagin has been charged with 21 federal counts of wire fraud, bribery, filing false tax returns and money laundering.

Mr Nagin, 56, mayor from 2002-10, came to national attention when Hurricane Katrina hit New Orleans in 2005.

Beginning in June 2004, Mr Nagin took payments, travel and other gratuities in exchange for city contracts and other favours, prosecutors said.

At least four Nagin associates have already pleaded guilty in the case.

"Mayor Nagin used his public office and his official capacity to provide favorable treatment that benefitted the business and financial interests of individuals providing him bribery/kickback payoffs," the indictment reads.

According to the federal indictment, Mr Nagin accepted more than $160,000 (£100,000) in bribes from local businessman Frank Fradella.

In exchange, Mr Nagin helped Fradella secure millions of dollars in contracts from the city in the wake of Katrina, including construction at the airport and sidewalk repair projects, prosecutors said.

Mr Nagin is also charged with accepting payoffs worth at least $60,000 from another businessman, Rodney Williams, who was given consulting and construction contracts with the city.

Fradella and Williams have already pleaded guilty in connection with the case and are expected to testify against the former mayor, according to the New Orleans Times-Picayune.

Private jets

The indictment alleges that over the course of his time in office, Mr Nagin travelled with his family to Hawaii and Jamaica on trips paid for by local businessmen.

He accepted free travel by private jet to Chicago, Las Vegas and New York City, according to the indictment.

Two former officials in Mr Nagin's administration have also pleaded guilty to corruption charges dating from their time at city hall.

Mr Nagin was a cable television executive before he entered public life in 2002.

He was backed strongly by white voters in his first run for mayor, styling himself as a candidate with bipartisan appeal and a progressive agenda.

Mr Nagin was thrust into the national spotlight during Hurricane Katrina and was re-elected to a second term as mayor in 2006.

Subsequently, a surge in violent crime, the slow pace of reconstruction, and the burgeoning corruption scandal at city hall undermined his popularity.

Since leaving office in 2010 he has stayed out of the political spotlight and has reportedly relocated to Dallas, Texas.