The schizophrenic Brazilian man killed by an Indonesian firing squad alongside Australians Andrew Chan and Myuran Sukumaran did not realise he was about to be put to death moments before he was gunned down.

"Am I being executed?" Rodrigo Gularte, asked the Irish priest appointed as his spiritual advisor as he was transported to the execution field.

Lawyers for executed Brazilian Rodrigo Gularte had filed a last-ditch appeal in the Administrative Court.

In an interview with Irish radio station RTE Father Charlie Burrows described Gularte's confusion during his last few hours alive.