A British Court of Inquiry convened on 7 July 1943, investigated the crash of Sikorski's Liberator II serial "AL 523", but was unable to determine the cause, finding only that it was an accident and "due to jamming of elevator controls", noting that "it has not been possible to determine how the jamming occurred but it has been established that there was no sabotage.". The Polish government refused to endorse this report, due to the contradiction about the cause not being determined but sabotage being ruled out.