Roughly a third of the companies that donated at least a million rubles ($15,000) last year to the ruling political party United Russia also happened to receive federal contracts for much larger sums, according to a new study by the independent movement “Golos.”

Golos identified 89 different companies that donated at least a million rubles to one of Russia's registered political parties in 2015 and also received a 2015-2016 state contract. Of those businesses, 80 were donors to a single party: United Russia, the party of Vladimir Putin and the country's leading political group. The largest contracts to these companies generally came from the Defense Ministry and Russia's defense industry.

A senior official in United Russia has denied any connection between donations to the party and the decisions to award large government contracts.

The news agency RBC has previously reported that United Russia received 5.1 billion rubles ($76.7 million) in 2015—1.7 billion rubles ($25.6 million) more than the year before. More than half of the party's income in 2015 was the result of a law passed in 2014 that more than doubled the amount of federal funding political parties receive for every vote they win in a general election (110 rubles, or $1.67, for every vote, instead of 50 rubles, or $0.75).

As a result of the 2014 law, United Russia completely restructured its funding scheme, eliminating the regional foundations that once supplied the bulk of its financing.

Eight business executives and entrepreneurs who are among United Russia's top donors were also winners in the party's primaries earlier this year. They'll stand in this September's general election for the State Duma.