Large numbers of Hungarian nationals were employed as a "slave workforce" by a bed-making firm which supplied household name retailers like John Lewis, Next and Dunelm Mill, a jury has been told.
Three men connected to the West Yorkshire business Kozee Sleep have gone on trial accused of people trafficking.
Leeds Crown Court was told how an investigation into Kozee Sleep, based in Dewsbury, and its subsidiary Layzee Sleep, based in Batley, began after two Hungarians, Janos Orsos and Ferenc Illes, were arrested over human trafficking allegations.
A jury was told how large numbers of Hungarian men were employed at Kozee Sleep's Dewsbury factory.
Prosecutors said company owner Mohammed Rafiq and two other men who had positions within the firm, Mohammed Patel and Mohammed Dadhiwala, knew that workers supplied to them by Orsos were trafficked.
Christopher Tehrani QC, prosecuting, said: "The prosecution submit that the three defendants were involved with Janos Orsos and his human trafficking organisation to source them cheap slave labour to work at Kozee Sleep and Layzee Sleep factories.
"The prosecution case is that the three defendants were aware of the circumstances of the Hungarian nationals who were working at these sites and went along with their exploitation as a slave workforce for their own and others' gain.
"The prosecution submits that this course of offending demonstrates a persistent campaign of exploitation involving many Hungarian men over a prolonged period of time.
"The motivation of both Janos Orsos, Ferenc Illes and these three defendants was financial."
Mr Tehrani told the jury: "The police investigation revealed that between 2011 and 2013 a large number of Hungarian nationals, who were, the prosecution say, vulnerable and/or desperate for work would be encouraged to seek employment in the UK with false promises about the employment on offer in the UK and the terms of the employment.
"They were promised good wages and that accommodation and food would be provided once they were in the UK working."
Mr Tehrani said: "Once they were in the UK, the Hungarian complainants faced a very different reality to what they had been promised.
"They found themselves living in shared, cramped and squalid accommodation with a large number of others. They were made to work at the respective businesses and other places for long hours, working anything between 10 to 16 hours per day, five to seven days per week. In the main, they did not receive their wages that they had been promised."
The prosecutor told the jury the men received £10 to £20 per week plus each house they were living in would receive about £20 a day for food.
Mr Tehrani said the business was in financial trouble.
He said: "It therefore had to reduce its costs and chose to do so by engaging Hungarian nationals to work at the factory for less than the set minimum wage, pay the wages to Janos Orsos and his associates and did nothing when they discovered that Janos Orsos was only paying a fraction of each worker's wages to the worker".
Rafiq, of Thorncliffe Road, Staincliffe; Patel, of Carr Side Crescent, Batley, and Dadhiwala, of Upper Mount Street, Batley Carr, all deny a single count of conspiracy to traffic individuals within the UK.
The trial continues.