A police raid of a house in Rotherham led to the discovery of £50,000.
The money was found by officers searching the homes of three men arrested as part of a child sexual exploitation probe in Rotherham.
Officers arrested the men in Rotherham yesterday on suspicion of indecent assault.
They have since been bailed.
The men were arrested by the National Crime Agency as part of Operation Stovewood, which was launched following the publication of a report in 2014 which found that 1,400 children had been abused in Rotherham between 1997 and 2013 while authorities failed to act.
An NCA spokesman said: "Following search activity at one address in Rotherham, a cash sum, believed to be in excess of £50,000, was found.
"One of the three men was further arrested and interviewed on suspicion of money laundering.
"All three have been bailed until December. The investigation is on-going."