Sparring over the Freedom of Information Act has started again on Capitol Hill.

With the 98th Congress just under way, Attorney General William French Smith and FBI Director William H. Webster renewed some of their calls for a cutback in the kinds of government records that are subject to disclosure under the 16-year-old law and in the kinds of people entitled to ask for them.

Testifying at a Senate hearing on organized crime, Smith and Webster complained that gangland figures have attempted to use the law from time to time to identify government informers. Webster said he favors legislation that "would permit us to deny felons access to our records and take other steps to protect the identities of our confidential sources."

The current law already permits the withholding of law enforcement records that would "disclose the identity of a confidential source," but Webster has long asserted that telltale details could still dribble out inadvertently.

Sen. Patrick J. Leahy (D-Vt.) suggested that the administration would be wise not to press for concessions beyond those in a compromise proposal suggested in the last Congress. It would have allowed withholding records that "could reasonably be expected to disclose confidential sources," and made other changes to protect organized-crime files.

"The protection of law enforcement information sources can be strengthened," Leahy added in a recent speech. But he argued that it was also time to counterattack the Reagan administration's more ambitious desires to see the FOIA "weakened or even crippled."

Speaking as the recipient of the Society of Professional Journalists' First Amendment Award, Leahy said he wished that President Reagan had a better appreciation of the FOIA, which Leahy said "puts a mammoth government on the same plane as any citizen it serves."

In any case, Leahy said, "I now agree that FOIA needs to be amended . . . to be more resistant to obstruction from within by a government hostile to its purposes."

Leahy said he intended to press for a bill that would genuinely improve the law, provide for more generous fee waivers, tighten the rules against unjustifed delays in handling FOIA requests and restore the public-interest balancing test in weighing requests for national security information. Reagan threw out the test by executive order last year.

The administration's underlying policy, Leahy said, "promotes secrecy as the norm dominating transactions with government."

"I think that the 98th Congress is ready for an affirmative FOIA bill, and not just a response to legislation designed to limit access," he said.