The four Democratic candidates hoping to defeat Mayor Bloomberg in November’s election have accepted donations totaling nearly $61,000 from individuals in the tobacco industry, a new analysis shows.

The front-runner and the only Democrat who has been leading Mr. Bloomberg in the polls, Fernando Ferrer, accepted $36,100 of those contributions, more than double what any other candidate took.

According to the analysis, conducted by the Tobacco-Free Kids Action Fund, the speaker of the City Council, Gifford Miller, was next with $17,175.

Rep. Anthony Weiner, whose House district includes parts of Brooklyn and Queens, accepted $6,350, and the borough president of Manhattan, C. Virginia Fields, took $1,350, according to the group.

The tobacco-free fund, which two years ago pushed for the mayor’s ban on smoking in bars and restaurants, demanded that the candidates return the money.

“We call on these candidates to return all contributions received from tobacco interests,” the executive director of the tobacco-free fund, William Corr, said in a statement. “Accepting tobacco contributions sends the wrong message.”

In late January, both Mr. Bloomberg’s campaign manager, Kevin Sheekey, and Mr. Corr singled out Mr. Ferrer for the tobacco money he accepted.

Mr. Sheekey was quoted in one newspaper as saying, “tobacco money is blood money” and “no one should run for mayor as the pro-cancer candidate.”

Around the same time, Mr. Ferrer’s campaign told The New York Sun that, if elected, he would not overturn the mayor’s two-year-old ban on smoking, which prohibits smoking in bars and restaurants.

The question of whether Mr. Ferrer would roll back the smoking ban came after a previous analysis found that a roster of cigar companies had donated about $25,000 to his campaign.

The publisher of Cigar Aficionado magazine, Marvin Shanken, helped Mr. Ferrer raise much of that money.

Democrats said yesterday they believe the Bloomberg camp was behind the fund’s analysis. A consultant to Mr. Bloomberg, Josh Isay, was at one point working for the Campaign for Tobacco-Free Kids.

Spokesmen said the Miller and Ferrer campaigns had no intention of returning the contributions.

“Mr. Ferrer has always made his decisions independently,” a spokesman for Mr. Ferrer, Chad Clanton, said last night.

A spokesman for Mr. Miller’s campaign, Reginald Johnson, said the speaker led the push that got the smoking ban through the council.

“It is unfortunate that Michael Bloomberg has chosen to hide behind political consultants, content on using this organization’s good name as a mouthpiece to score a cheap political point,” he said.

Mr. Bloomberg’s spokesman, Stu Loeser, said the mayor’s campaign had “absolutely nothing at all to do with this.”