The world's top four DRAM makers , Samsung Electronics and Hynix Semiconductor Inc., Micron Technology Inc, and Infineon Technologies AG -- are believed to be under investigation.

The probe mirrors a similar investigation in the United States. Prosecutors in the United States are investigating an alleged price-fixing conspiracy among the world's major DRAM makers that may have occurred before a sharp increase in prices two years ago.

DRAM prices have subsequently collapsed and forced DRAM operations into losses. Now some DRAM makers are facing criminal price-fixing charges while others are considering whether to try and make plea bargains with prosecutors and risk heavy fines, the story is reported to have said, citing lawyers close to the case.