As American retailers face mounting pressure to join a landmark plan to improve factory safety in Bangladesh, newly found documents indicate that apparel had been produced for Wal-Mart at one of the operations in the factory building that collapsed last month, killing more than 1,100 workers.

The Bangladesh Center for Worker Solidarity has provided The New York Times with photos of several documents not disputed by Wal-Mart that were recovered in the building’s rubble, showing that a Wal-Mart contractor from Canada had produced jeans last year at the Ether Tex factory, which had been situated on the fifth floor of the collapsed Rana Plaza building.

While both the contractor and Wal-Mart denied any knowledge of the production orders there, Wal-Mart on Tuesday announced that it would put in place new safety measures at the factories it was using in Bangladesh.

Saying it was unwilling to sign on to the broad safety plan embraced by more than a dozen European companies this week, Wal-Mart said its factory monitors would “conduct in-depth safety inspections at 100 percent” of the 279 factories it uses in Bangladesh and publicize the results on its Web site.