ROME (Reuters) - More than 40 people have been held in Italy over migrant visa fraud, police and prosecutors said on Wednesday, weeks after Prime Minister Giorgia Meloni complained that mafia groups were exploiting the system for profit.

Forty-four people were apprehended, including 13 put in jail, 24 under house arrest and seven in custody. They were charged with various crimes, such as criminal association aimed at abetting illegal immigration, money laundering and false invoicing.

A further 10 suspects were banned from business activities for 12 months.

According to a statement by prosecutors from the southern city of Salerno, near Naples, the suspects filed fraudulent visa applications on behalf of migrants, who need the sponsorship of employers to start the process.

They filed "around 2,500" applications from 2020 onwards "based on non-existent or falsified data", prosecutors said, adding that migrants paid as much as 7,000 euros ($7,575.40) each to push the process along through various bureaucratic hoops.

Assets worth around 6 million euros were seized as profits from the alleged crimes, prosecutors said, indicating that some of the suspects accused of money laundering were linked to the Camorra, the Mafia in and around Naples.

Speaking to reporters, Salerno Chief Prosecutor Giuseppe Borrelli said investigations were accelerated after Meloni in June said she had reported her concerns about possible visa fraud to the national anti-Mafia prosecutor.

As part of its tough stance on immigration, Meloni's rightist government has passed an array of measures to curb migrant arrivals, but has also expanded legal immigration channels in response to growing labour shortages.

Last year, it raised quotas for work visas for non-EU citizens to a total of 452,000 for the period 2023-2025, an increase of nearly 150% from the previous three years. In 2019, before the COVID-19 pandemic, Italy issued just 30,850 visas.

The system is massively oversubscribed, with 151,000 places available for 2024 alone, and nearly 244,000 requests made in the first 10 days of the opening of the procedure, according to the interior ministry.

Last month Meloni said a disproportionate amount of applications had come from Campania - the economically depressed region comprising Naples and its Camorra mafia - raising alarm bells.

Migrant rights advocates say excessive red tape facilitates visa abuse, and, calling for a reform of the system, say it typically benefits undocumented migrants already in Italy, who use the quotas to legalise their situation.

($1 = 0.9240 euros)

(Editing by Sharon Singleton)

By Alvise Armellini