The finance police said Domenico Lucano had been allegedly organizing the so-called "marriages of convenience" between local men and foreign women so that the latter could stay in Italy, the finance agency said.
The investigation against the mayor was launched last year after the prefecture of Reggio Calabria city had sent a commission to Riace, which allegedly detected the misuse of public funds dedicated to the allocation of migrants.
Lucano has been accused of aiding illegal migration and fraudulently awarding contracts for waste disposal.
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In early August, Prime Minister Giuseppe Conte said that in just two months since his cabinet began working, the number of migrants landing on Italy's shores had fallen by 80-85 percent.