Prosecutors have already told one lawmaker, Rep. Robert W. Ney (R-Ohio), and his former chief of staff that they are preparing a possible bribery case against them, according to two sources knowledgeable about the matter who spoke on the condition of anonymity.

The 35 to 40 investigators and prosecutors on the Abramoff case are focused on at least half a dozen members of Congress, lawyers and others close to the probe said. The investigators are looking at payments made by Abramoff and his colleagues to the wives of some lawmakers and at actions taken by senior Capitol Hill aides, some of whom went to work for Abramoff at the law firm Greenberg Traurig LLP, lawyers and others familiar with the probe said.

Former House majority leader Tom DeLay (R), now facing separate campaign finance charges in his home state of Texas, is one of the members under scrutiny, the sources said. Sen. Conrad Burns (R-Mont.), Rep. John T. Doolittle (R-Calif.) and other members of Congress involved with Indian affairs, one of Abramoff's key areas of interest, are also said to be among them.