On the eve of the 39th birthday of Carl E. Heastie, then a little-known assemblyman from the Bronx, his campaign paid a $270 tab for “food” at Happy Valley, a Manhattan nightclub that did not sell food but was popular for its throbbing dance floor and caged go-go dancers.

When Mr. Heastie’s BMW needed repairs, which was about every 10 weeks, he charged his campaign for the work, more than $30,000 over nine years. During that time, he also billed the state $51,200 in mileage reimbursements, money meant to cover repairs and other costs for trips to and from Albany.

And when it came time to file reports on how his campaign had spent its money — a total of nearly $1.1 million since he took office in 2001 — Mr. Heastie often did not detail where that money had gone. His filings contained no explanation at all for who ultimately received nearly $150,000 from the campaign — mostly, he asserted, because the expense amounts were less than $50 and did not need to be itemized under state rules, according to an analysis of his financial disclosure records by The New York Times.

Mr. Heastie’s campaign spending received little attention during his first 14 years in office. In February, however, he became Assembly speaker, one of the most powerful officials in state government. His sudden ascendance came as his colleagues scrambled to replace Sheldon Silver, the longtime speaker who had been arrested on federal corruption charges.

Soon after becoming speaker, Mr. Heastie, a Democrat, pledged to restore trust in Albany by enacting ethics reform. But a close review of his campaign disclosure records suggests he has frequently used political donations to burnish his lifestyle.