Police who pulled a van over for a stop-check on a motorway found a large stash of suspected MDMA pills and powder.
The van was stopped on the M62 at Junction 7, near Rainhill, at about 19:20 BST on Tuesday to “check documentation”, Merseyside Police said.
The force said thousands of pills and “multiple kilos” of powder were seized and would now be forensically examined.
A 41-year-old man, from Crosby on Merseyside, has been arrested on suspicion of possessing a Class A drug with intent to supply and driving while disqualified.