Updated

Attorneys for two Texas death row inmates are challenging the state's position that its supplier of a new batch of execution drugs should be kept secret.

An emergency hearing is set for Thursday before a state judge in Austin. Lawyers for two prisoners who would be the first executed with the replenished stockpile of pentobarbital filed a lawsuit Wednesday demanding the Texas Department of Criminal Justice name the provider.

The lawyers represent convicted killers Tommy Lynn Sells and Ramiro Hernandez-Llanas, who are scheduled to die April 3 and 9 respectively.

Their lawsuit contends the prisoners cannot evaluate the risk that could result in them being subjected to unconstitutionally cruel pain.

Texas prison officials contend the identity of the new drug source should be withheld to keep the supplier from threats.