WASHINGTON — The top executive for the Maine defense contractor accused of hindering a congressional contract-fraud investigation said Sunday that the charge is unfounded and produced documents to back up his claim.

“We don’t want to impede those investigators in any way,” William E. Haggett, chairman and chief executive officer of Bath Iron Works, told The Associated Press.

Haggett called a news conference to respond to charges by Rep. John Dingell that the Navy contractor has refused to provide the congressional General Accounting Office with documents as its investigation continues.

Dingell, D-Mich., also said BIW has not allowed investigators to interview employees unless the GAO promises to withhold the information from Congress.

BIW is building the Navy’s new $1.2 billion guided-missile destroyer. Dingell, the chairman of the House Energy and Commerce subcommittee on oversight and investigations, has been highly critical of the Navy’s plans to buy 33 of the DDG-51 destroyers at a cost of about $30 billion.

Haggett distributed a letter Sunday to Milton J. Socolar, GAO’s acting comptroller general, that disputes Dingell’s assertions.

Haggett’s letter, dated May 1, said, “GAO would be given free access to BIW employees,” and that no shipyard managers would be present while those shipyard employees are interviewed.

The letter, outlining a tentative agreement on the how the GAO investigation would be conducted, also noted BIW’s request that information on the investigation be withheld by the GAO until its probe is complete.

That “is obviously not an attempt to withhold results of any investigation from the Congress,” said the letter.

Haggett said he did not want information released to Congress “piecemeal” because it could be taken out of context and could be misleading. His letter, however, said that GAO would be expected to turn over to the Justice Department “immediately” any evidence of criminal misconduct.

His letter charged that “preliminary, inaccurate, misleading or proprietary information” from past audits has been released by members of Dingell’s committee staff.

Haggett’s letter said that “any suggestion that a (congressional) hearing is necessary because BIW has stonewalled your investigators or refused to cooperate with GAO would be a gross distortion of the truth.”

He said BIW has cooperated with the GAO and the Defense Contract Audit Agency, which are looking into the allegations by Dingell and those made anonymously through a whistleblowers’ hotline. But Haggett added that he’s confident the investigation will find no evidence of wrongdoing.

Dingell, in a letter to Defense Secretary Dick Cheney, said it was time the Navy got tough with the contractor.