A white car travelling eastbound was stopped near junction 37 of the motorway near to Howden around 6pm when the drugs were found.
Around ten kilogrammes of controlled drugs including class A and class B substances were found. Tests are being done on these at the moment.
Initial estimates are that the drugs could have a street value of up to £300,000.
A man has been arrested and is in custody.
Detective Chief Inspector Mark Kelk said: “I’m delighted that these drugs have been found and taken off our streets.
“It is a significant seizure of drugs that were destined for the streets of our cities and towns. They clearly could have had a serious impact on our communities.
“Our priority first and foremost is the safeguarding of people in those communities.
“This is another good result by our officers. We continue to tackle individuals who are concerned in the supply of drugs and drug related crime.”