Four senior Spanish police officers have seemingly contradicted the official version of who gave the orders to charge at voters during the October 1, 2017 Catalan independence referendum crackdown.

Testifying as part of those investigated by a local Barcelona court on Thursday, they said there was a head whose code name was 'Marte' who gave the specific instruction to charge at voters from 8 am, an hour before the vote began.

The then secretary of state for Security, José Antonio Nieto, and the head of Guardia Civil police force at the time, Diego Pérez de los Cobos, have repeatedly maintained that no one gave the specific order to begin the crackdown.

One of the human rights lawyers seeking a conviction for the crackdown, Anaïs Franquesa, said that now it is "obvious" that orders were given – for the human rights groups, the Spanish riot police head at the time, José Miguel Ruiz Iguzquiza, could be the person behind the code name 'Marte.'

"There were at least two orders from the time the police intervention began to when it ended, that is abundantly clear," said Franquesa.

According to her, police officers testified that they were told to act "with proportionality and according to the basic principles of action, which are common sense, need, and progressive use of force."

Four of them testified on Thursday, while four more will testify on Monday. They are all senior officers in charge of the police operation at 27 of Barcelona's polling stations.

Overall, in Catalonia, 1,066 voters were injured due to the police charges, according to the Catalan health department.