CBS News producer Mary Mapes prodded a senior aide to Sen. John Kerry to speak to the retired National Guard officer who provided now-discredited documents on President Bush's military service, according to the Kerry aide and CBS.

In an interview yesterday, Kerry strategist Joe Lockhart said Mapes called him Sept. 4, four days before the report was broadcast on CBS' 60 Minutes. According to Lockhart, Mapes told him CBS was ready to "move the National Guard story forward" on Bush, whose service record includes significant gaps. Lockhart said she told him she had documents to back her story.

"She didn't tell me what was in them, and I didn't ask," Lockhart said yesterday. Lockhart said Mapes did give him the telephone number of a source on the story - retired Texas National Guard Lt. Col. Bill Burkett, a vociferous Bush critic - and told him that Burkett hoped to receive a call from the Democratic campaign.

Lockhart said he called Burkett the next day, Sept. 5, and got an earful about how the Kerry campaign had failed to fend off attacks by a group called Swift Boat Veterans for Truth. Kerry was put on the defensive in August by the group's accusations that he had inflated his combat record. The conversation lasted three or four minutes, Lockhart said, and it was typical of the comments of many veterans sympathetic to Kerry, the Democratic nominee for president. He said they did not speak of Bush's National Guard record or the documents.

Mapes did not reply yesterday to messages seeking comment, and Burkett, by e-mail, declined to comment.

The network conceded yesterday that Mapes had contacted Lockhart on Burkett's behalf.

In an interview with USA Today, Burkett said Mapes had promised to help him get in touch with the Kerry campaign as part of an arrangement.

CBS News President Andrew Heyward has announced that he will commission an outside inquiry into how the flawed story reached the air.

"It is obviously against CBS News standards, and those of any other reputable news organization, to be associated with any political agenda," said network spokeswoman Kelli Edwards. "To the best of our understanding, there was no deal, but this is one of many issues the independent review will be examining."

But the journalist's involvement in coordinating the call between Lockhart and Burkett could further damage public trust in the network's objectivity during a heated political campaign.

"I'm really heartsick she made that call. It has the air of some kind of conspiracy behind it to help Kerry," said Sandy Socolow, a former executive producer of the CBS Evening News with Dan Rather and his predecessor, Walter Cronkite. "She was trying to manipulate the political process in some way that's not clear to me."

Burkett had expected CBS to pay him for his collaboration on the Bush story, according to Dennis Adams, a retired lieutenant colonel who served with him in the Guard. Burkett was angered by what he saw as the network's failure to do so, said Adams, who said he spoke to Burkett on Sunday.

"He had a contract with them," said Adams, although he said he did not know whether it was a verbal or written agreement. "He's had to pay a lot of money out of his own pocket. He has felt that strong about what he was doing."

CBS said no such payments were made or contemplated. "From the start, it was made clear to Bill Burkett that we do not compensate - in any way - the source or the subject of an interview," Edwards said.

The report broadcast Sept. 8 alleged that Bush had received preferential treatment in entering the Texas Air National Guard in 1968 and in avoiding his military obligations in 1972 and 1973. Documents said to come from the personal file of Bush's squadron commander appeared to verify that he had been disciplined but was protected by pressure from powerful patrons in the Guard.

On Monday, CBS News and anchor Dan Rather apologized for relying on documents provided by Burkett. Rather told viewers he could no longer vouch for the authenticity of the records after Burkett acknowledged misleading the network on how he obtained them.

For the 10-day period leading up to that admission, CBS endured a barrage of criticism for relying on the memos. Experts interviewed by other mainstream news outlets picked apart inconsistencies in the memos which indicated that they had been created on modern computers, not typewriters in use at the time they were allegedly written.

Prior to its apology on Monday, however, CBS had vigorously defended the story. And Rather had been particularly dismissive of "partisan political operatives" whom he said were its chief critics.

White House aides stayed quiet on the subject yesterday, after several days of questioning whether the Democrats had been involved in putting together the 60 Minutes story. In comments to CBS, Ed Gillespie, chairman of the Republican National Committee, suggested that there might be ties between the Kerry campaign and the network.

In yesterday's interview, Lockhart said he did not know Mapes before the call. Asked why he would call Burkett at her request, Lockhart said: "I would hate to wake up Nov. 15th" - two weeks after the election - "and find out this guy had had useful information."

Sun staff writer Ellen Gamerman contributed to this article.