WASHINGTON (Map, News) - In an escalating battle between the Democratic presidential candidates over what information should be made public, Barack Obama released tax returns dating to 2000 on Tuesday and challenged Hillary Clinton to follow suit.

“Senator Clinton recently claimed that she’s the most transparent figure in public life, yet she’s dragging her feet in releasing something as basic as her annual tax returns,” Obama spokesman Robert Gibbs said. “Senator Clinton can’t claim to be vetted until she allows the public the opportunity to see her finances — particularly with respect to any investment in tax shelters.”

The Clinton camp said she will release her 2006 returns in the days leading to the April 22 Pennsylvania primary but has not committed to disclosing any of the other returns filed after President Clinton’s departure from the White House.

The Obama campaign and other critics have suggested the Clintons are attempting to hide potentially damaging information. The Clintons’ personal fortune became a major issue in January when Hillary Clinton lent her campaign $5 million out of the couple’s joint finances.

It was disclosed around that time that Bill Clinton was set to receive a multimillion-dollar payout from his investment in Yucaipa Cos., a firm run by billionaire Ron Burkle that invests mostly in supermarket chains. In recent months, Burkle has been accused of conducting several questionable business deals involving Yucaipa that could be embarrassing for the Clintons.

The Clintons have responded to the attacks by the Obama campaign concerning their tax returns by calling on him to release all of his records relating to his business relationship with indicted businessman Antoin Rezko.

The tax returns released by Obama do not include all of the years — 1997 to 2004 — that he spent in the Illinois state Legislature, nor do they cover the years before he entered public office.

Gibbs said that what the candidate made public “correlates with what the Clintons have pledged at some unknown date in the future they will release.”

The returns, filed jointly by Obama and his wife, Michelle, show incomes mostly in the low six figures until 2005, when Obama’s three-book deal with Random House and royalties from an earlier publication, “Dreams of My Father,” netted the couple $1.2 million.

Michelle Obama’s income as a hospital administrator also increased significantly, from $122,000 in 2004 to $316,000 after she was promoted in 2005, contributing to a total income for the Obamas of $1.67 million that year. It was the only time the couple earned more than a million dollars in the years covered by the tax returns.

The Obama campaign, which two months ago began subtly suggesting Clinton release her tax returns, is now attacking her full force over her failure to release the documents.

“Send someone to Kinko’s to photocopy her tax returns and post them immediately on their Web site,” Gibbs suggested.

sferrechio@dcexaminer.com