Federal elections officials have fined Ted Cruz’s Senate campaign $35,000 for failing to report more than $1 million in bank loans he used to finance his successful long-shot race in Texas in 2012.

The penalty was part of a settlement reached by the Federal Election Commission and Mr. Cruz’s Senate campaign in February and disclosed in a letter this week from the commission to the Campaign Legal Center, a watchdog group that had filed a complaint over the unreported loans.

The fine comes more than three years after the loans were revealed by The New York Times in January 2016 and became a political issue for Mr. Cruz during the Republican presidential primary. The Times article showed how Mr. Cruz claimed to have liquidated his family’s wealth and put it into his 2012 campaign, when in fact he had borrowed money from Goldman Sachs and Citibank without disclosing it on campaign filings.

Mr. Cruz initially described his actions as a clerical oversight, saying he had disclosed the loans on a different set of reports, filed with the Senate, that detailed his personal income, assets and debts. But those reports did not explain what the loans were used for, and he failed to disclose them, as required, on filings with the election commission, which would have showed the $1,064,000 from the two banks was used for campaign purposes.