US and foreign banks were not unwitting victims of circumstance but deliberately culpable in the financial meltdown that engulfed the United States last year, a campaign group said Wednesday.

The Center for Public Integrity named 25 "subprime" mortgage companies whose risky lending was blamed for the US property market collapse and the subsequent global economic crisis.

Many of the lenders were either controlled by US and European banks, or could not have indulged in their high-risk lending spree without the connivance of banks, the investigative journalism group said in a new study.

"The mega-banks that funded the subprime industry were not victims of an unforeseen financial collapse, as they have sometimes portrayed themselves," the center's executive director Bill Buzenberg said.

"These banks were deliberate enablers that bankrolled the type of lending that's now threatening the financial system," he said.