There is an obvious but negligible financial connection between Mayor David Maher and the developer pushing the city to grant 300,000 additional square feet in Kendall Square: a single campaign contribution of $250 for Maher’s most recent run for reelection.

Maria Cantalupa, of Winchester, donated the money Oct. 25, according to records at the state’s Office of Campaign & Political Finance. Michael Cantalupa, of the same address, is senior vice president of development at
Boston Properties Inc., the company with the plans in Kendall Square.

There have been whispers about a connection this week.

“There are cynics out there that believe that anyone that makes a contribution owns a politician. And I would say that’s just absolutely ridiculous,” said Maher on Wednesday, before a meeting of the Ordinance Committee at which Michael Cantalupa spoke.

The committee issue — changing zoning law to allow 300,000 more square feet into the so-called MXD District for an expansion of The Broad Institute — was raised by city councillor Leland Cheung, who tried to pass a policy order Monday that would have sent officials into the Wednesday meeting with information and opinions from the city manager and solicitor. Maher used his “charter right” to veto Cheung’s request.

But not because he’s protecting a developer, he said.

“I’ve never sold a vote on anything. I have been consistently supportive of our business community while representing the best interests of the neighbors and neighborhoods,” said Maher, who served four terms on the School Committee before being elected to the council in 1999. This is the first term he has served as mayor, a position voted by his fellow councillors.

Cambridge political watcher Robert Winters, who maintains campaign finance data on his website, said Thursday that “a $250 donation probably wouldn’t affect much of anything.”

“I wouldn’t single out any particular city councillors, either, but I would say that it is acknowledged and recognized by many people that a sizable number of those maximum campaign contributions ­— typically the $500 variety — does seem to be highly correlated with the way people vote on such things as zoning petitions,” Winters said. “Were the individual councillors going to vote for those changes anyway, and this is just a way to say, ‘Thanks for being a good guy and consistent and wonderful and all that’? I’m not sure it would ever be easy to come up with a ‘Which came first, the chicken or the egg’ answer.”

The Cantalupa donation, of course, didn’t even reach that $500 maximum.

A high degree of out-of-town contributions do, Winters said, but it remains unclear what the benefit is — even on a large zoning issue such as the recent Alexandria decision, where he saw significant money had flowed from people connected with the issue.

The state data don’t show the same situation with the MXD District, and Maher rejected a direct connection.

“Certainly if there was a contribution made in 2009 for a project that is just coming before the council in 2010, obviously there is no correlation between the two … Boston Properties is one of the biggest property owners in Cambridge. I think if you looked on many people’s campaign finance reports, you will see that business people make donations,” Maher said. “I’ve known Mike Cantalupa for many years. I think if you went back over time, he has probably made contributions to several candidates, including me. Off the top of my head I couldn’t tell you, but it’s probably fair to say that he or his wife, whoever signed the check, made a contribution in the last campaign. But that’s along with several hundred people who made contributions.”

The state’s records going back to 2002 show that in Cambridge the Cantalupas have donated to Maher only once; to Anthony Galluccio twice in 2002, for a total of $500; to councillor Tim Toomey once, in 2004, for $250; to Michael A. Sullivan once, in 2005, for $100; and to Marjorie Decker twice, in 2005 and last year, each time for $250.

There is still the potential for “bundling,” meaning employees of Boston Properties could have been urged to donate separately to promote Maher as a candidate. A quick analysis with an OCPF employee found no evidence of this, and another look at campaign finance data gathered by Winters bears that out.

Maher went into the campaign with the second-highest bank balance, $12,828, but this was less than half what Toomey had ready to go. And at $37,382, he was sixth in spending, behind Decker, Henrietta Davis, Ken Reeves, Toomey, and Denise Simmons. But at 54 percent, he is 13th out of 21 in contributions from Cambridge residents — or 13th out of 16 if the list leaves out those candidates who raised and spent less than $200.

A simple Google search for associations between “Maher and Cantalupa” produce what could be considered false positives. For instance, last year Michael Cantalupa was listed as an officer on the board of directors at the nonprofit A Better City, alongside Christopher W. Maher, a vice president of development at
Boston Garden Development Corp.; and in a decade-old article from the Boston Business Journal, Michael Cantalupa is quoted speaking well of a fledgling development firm that includes a Tom Maher.

Neither are relatives, David Maher said Wednesday. His siblings are Catherine, Mary and William.

Michael Cantalupa was called Thursday for comment.