WASHINGTON — The Justice Department’s internal ethics watchdog said Thursday that two prosecutors in the bungled corruption case against then-Sen. Ted Stevens engaged in reckless professional misconduct by failing to disclose information favorable to the lawmaker, who eight days after his 2008 conviction lost re-election to the seat he held for 40 years.

The Office of Professional Responsibility, however, did not find that the misconduct was intentional.

A career Justice Department official decided one prosecutor should be suspended for 40 days without pay and the second prosecutor should be suspended for 15 days without pay. They can appeal to the independent Merit Systems Protection Board.

The office found no professional misconduct by other prosecutors in the Stevens case.

A jury convicted Stevens on Oct. 27, 2008, of seven felony counts of lying on Senate financial disclosure documents to hide hundreds of thousands of dollars in home renovations and gifts from wealthy friends. Stevens, the longest-serving Republican in the Senate at the time, was defeated eight days later by Democrat Mark Begich.

The judge in the case dismissed Stevens’ conviction in April 2009 after the Justice Department admitted misconduct. Stevens died in a plane crash on Aug. 9, 2010.

In March, a court-appointed special prosecutor, Henry Schuelke, declined to recommend criminal contempt charges over government misconduct in the case. But, unlike the Justice professional responsibility office, Schuelke did conclude that the two prosecutors, assistant U.S. attorneys Joseph Bottini and James Goeke, had intentionally withheld key information from the defense.

Justice’s professional responsibility office found that their supervisor, Brenda Morris, exercised poor judgment by failing to supervise the review of material for possible turnover to the defense, but no other discipline was imposed on her.

The government’s star witness in the Stevens prosecution, Bill Allen, testified that he oversaw extensive renovations at Stevens’ home and sent his employees to work on it. Allen is the millionaire founder of VECO Corp., an Alaska company that provided support for oil producers. Stevens’ defense was that the senator and his wife understood that VECO’s costs for its employees’ work on the renovation were included in the bills the senator received.

The OPR said in a report that Bottini failed to provide Stevens’ lawyers with information from Allen that was inconsistent with Allen’s later interviews and trial testimony.

In addition, the report also said Bottini failed to disclose information in an FBI interview summary and an Internal Revenue Service interview memo regarding Stevens’ willingness to pay bills that VECO might have provided. Bottini also was found to have failed to disclose information from a construction supervisor who said he thought that VECO’s costs would be added to the invoices sent to Stevens for payment.

The report found that Goeke failed to disclose the information about the construction supervisor.

Bottini is a federal prosecutor in Alaska, and Goeke is a prosecutor in the Eastern District of Washington state.

The OPR report “is further evidence” that Schuelke’s report issued in March “was flat wrong when he accused Joe of intentionally violating the rules,” said Bottini’s lawyer, Kenneth Wainstein.

In a letter to the Justice Department, Goeke’s lawyers rejected the OPR report’s finding of misconduct. Goeke reasonably believed that the construction supervisor’s prior statements to the grand jury would be disclosed to the defense, said the letter.

Schuelke’s report to the judge described a prosecution team that was badly mismanaged and under enormous pressure. Stevens, in his effort to save his Senate seat, demanded a speedy trial so that the outcome would be known before Election Day in 2008.

Senate Judiciary Committee Chairman Patrick Leahy, D-Vt., said he plans to hold a hearing June 6 to learn “what steps the department is taking to ensure sure that what happened in the Stevens case does not happen again, regardless of the prominence of the defendant.”

Since the Stevens debacle ended in April 2009, the Justice Department has devoted substantial time and attention to training prosecutors and federal agents about their obligations to turn over evidence favorable to a defendant, a process known as “discovery.”

Regardless of experience, 6,000 federal criminal prosecutors go through two hours of discovery training each year. Last year, the Justice Department provided discovery training to more than 26,000 federal law enforcement agents and other officials, mainly from the FBI, the Drug Enforcement Administration and the Bureau of Alcohol, Tobacco, Firearms and Explosives.

The Justice Department says a legislative remedy is unnecessary.

Sen. Lisa Murkowski, R-Alaska, has introduced the Fairness in Disclosure of Evidence Act, which would require early release of evidence favorable to the defense. The legislation requires disclosure of such evidence without delay after arraignment. Evidence favorable to the defense that is uncovered later in the case must be turned over as soon as reasonably possible.

Murkowski’s legislation also would require prosecutors to disclose material that reasonably appears to be favorable to the defendant. That addresses the practice by prosecutors of disclosing favorable evidence only if it is deemed material to the guilt or innocence of a defendant.