A money laundering scam was uncovered after police pulled over a vehicle with tens of thousands of pounds of “contaminated” cash.

On October 7 2014, police officers pulled over a silver Honda on the M40 in Denham. The only person in the vehicle was 25-year-old Muhammed Mansur Ahmad, of Topsham Road, London.

Police said he was insured to drive the car but was not the registered keeper.

On searching the vehicle, officers found two carrier bags with cash totalling £56,080, which had traces of cocaine, MDMA and amphetamines.

Ahmad was arrested on suspicion of money laundering. He said he lived in Topsham Road, London, which was owned and occupied by Muhammed Islam, 53, and his wife, Saima Shahzadi, 38.

Officers searched the address and found a shoebox in the tumble dryer containing banking paperwork, cash bundle tags and bank details written on pieces of paper.

More bank deposit receipts and bank deposit envelope stubs were also found in the property.

Islam was arrested on October 10 2014. He denied knowledge of the cash found in the car. He told police he employed Ahmad at the shop, though he did not know him that well.

Ahmad’s mobile phone was examined by detectives and was found to have pictures of bank receipts on it, proving that deposits had been made.

Police said according to this evidence, Ahmad had banked a total of £96,135 between May 27 2014 and September 30 2014.

The bank deposit receipts and envelope stubs found at Topsham Road showed that “large sums” of money were being paid into several different bank accounts during a very short period of time – according to these it appeared that at least £233,661 in cash had been deposited at various banks between September 23 2014 and October 7 2014.

Police said many of the envelope deposit stubs were not dated and feared the amount could have been higher.

They said they also found “unexplained” money transfers from Ahmad to his alleged employer Islam of £37,827.

Ahmad absconded while on bail and has not been found since.

Both Islam and Shahzadi pleaded not guilty and were tried at Aylesbury Crown Court. They were found guilty and sentenced on March 3 this year.

Islam was convicted of entering into a money laundering arrangement and three counts of handling stolen goods; he received a total of five years and nine months’ behind bars.

He was also ordered to pay a confiscation order after the judge found that he had pocketed £279,573 and that he had assets in excess of this amount.

He was given three months to pay or serve two years behind bars in default.

His wife was convicted of attempting to pervert the course of justice and jailed for eight months.

Detective Inspector Gavin Tyrrell, head of Thames Valley Police’s economic crime unit, said: “This was a complex investigation where our financial investigator had to follow the paper trails of bank deposits but were not given credible reasons for the deposits.

“No reasons were also given for why Ahmad, who was apparently an employee of Mr Islam, paid his employer more than £37,000.

“Money laundering is a serious crime and anyone found guilty of it should expect to pay heavily for their offences.”