BOSTON--Two weeks after the Gardner Museum theft, investigators had little progress to report in the probe of the biggest art heist in history, and insurers disputed the museum's claim that it could not afford to insure the stolen works against theft.

The works were stolen in the early morning hours of March 18, when two men dressed as police officers talked their way into the museum and tied up two security guards.

The thieves made off with 11 paintings and prints by such artists as Rembrandt, Vermeer, Manet and Degas, and swiped an ancient Chinese vase and a gilded eagle from the flag pole of a Napoleonic flag.

The FBI released composite sketches of the two thieves, two international auction houses, Sotheby's and Christie's, posted a $1 million reward for information leading to the return of the works and the museum received tips on their whereabouts.

Yesterday FBI special agent Paul Cavanagh said investigators continued to receive tips, but were still not close to a break in the case.

"We still have plenty of work to do," Cavanagh said. "We're looking into everything and we're not discounting anything."

The stolen works were considered too well-known to be sold on the open market, and the heist was estimated to be worth hundreds of millions of dollars.

But the museum named after millionaire iconoclast Isabella Stewart Gardner announced days after the break-in that the works were not insured for theft.

Museum officials said the cost of such insurance would exceed the museum's $2.8 million operating budget. Also, Mrs. Gardner's will bars the museum from buying or installing replacements for stolen works even if they were insured, they said.

Art insurers said, however, that theft insurance was affordable even for small museums, and disputed the Gardner's claim that it would cost millions each year.

"I don't know why they'd make such a statement," said Carl Allen, chairman of Allen Insurance Associates, a Los Angeles firm that insures about 100 museums nationwide. "Those statements are just exaggerations."

Both Allen and Huntington Block, president of a Washington, D.C., firm that insures 285 museums, said a $100 million policy covering theft, fire and any other loss or damage would run about $150,000 annually.

"That's a pretty normal figure," Block said. "I don't know where the Gardner people got the idea it would cost millions."

Museum spokesman Barry Wanger said Gardner officials reviewed the museum's insurance policies about two years ago. He said they had received widely varying cost estimates and concluded that protection against theft was too expensive.

"There were all sorts of figures being bandied about," Wanger said. "It all depends on who you talk to."

Wanger said the museum's board of trustees last week formed a subcommittee to examine the museum's security measures and insurance policies. He said theft insurance would be one of the areas discussed.

The outlook for the recovery of the Gardner pieces is better than average because they are so well-known, but the outlook is still not bright, investigators said.

"Well-known works are found slightly more often, but about 80 percent of stolen art is never recovered," said Robert Spiel, a private security consultant in Chicago and former FBI agent specializing in art theft.

"When you come down to it, the odds are against you," Spiel said.