Illegal migrants were employed by gangs to work on Sting's luxury wine estate in Tuscany, according to an Italian police investigation.
Prosecutors said they believe the pop star was unaware that around 30 to 40 people whose asylum applications had not been processed worked on his land, reportedly for as little as four euros (£3.60) an hour.
The Police frontman has owned the 865-acre Il Palagio estate near Florence, used to grow olive trees, grapes and other fruit, for 16 years.
Labourers from Pakistan and African countries who had not yet been granted the right to settle in Italy were contracted to work there last year by a company associated with gangs, the prosecutor leading the investigation told The Telegraph.
The newspaper said 11 people are being investigated over a number of charges, including commercial fraud, profiting from illegal labour and issuing false financial records.
Sting said he was “saddened and distressed to learn that an independent company leasing some of our fields may have been involved in questionable labour practices“.
“I fully expect that Italian law will take its course and bring the matter to court,” said the musician, whose twelfth solo album, released next month, includes songs about the refugee crisis.
The wide-ranging police investigation into labour practices in the region found hundreds of migrants had been illegally recruited between 2011 and 2016 by a group of Pakistanis led by Tariq Sikander, according to Italian news agency Ansa.
Antonio Sangermano, at the head of the wide-ranging investigation into labour practices in the region, told The Telegraph Sting “had no knowledge of this and we believe he was not even in Italy at the time.”
“He is not part of our inquiry. But we are looking into exactly who employed these workers on the estate,” he said.
The investigation started last May after two refugees reported the operation, according to Corriere della Sera.
They said a vehicle carried the migrants staying in the town of Prato straight to vineyards before dawn each day.
The newspaper reported that three directors of the company Coli Spa, believed to be at the centre of the operation, have been arrested.
