Rep. Bart Stupak, D-Mich., chairman of a House panel investigating the Gulf oil spill, says BP won't let his committee talk to several employees who may have critical information about what led to the catastrophe.

Stupak tells The Associated Press there are a half-dozen people his committee wants to question but hasn't been able to because BP is citing its own investigation as a reason deny access to the employees.

As of yet, he says, the panel isn't ready to issue subpoenas.