Konrad Mizzi's bid not to testify in the public inquiry into journalist Daphne Caruana Galizia's assassination has been quashed by the inquiry's board. 

Judges Michael Mallia, Abigail Lofaro and Joseph Said Pullicino ordered the former high-profile minister to appear before the board on Friday at 9.30am.

In a statement earlier on Thursday, Mizzi indicated he will not cooperate with the inquiry, describing it as a "charade" that has been politicised.

He said the inquiry has deviated from its original purpose, and was being used to pursue a purely political agenda.

Mizzi also filed an application asking not to appear at the inquiry, denying any involvement in the murder and offering his condolences to the family.

He said he had always been available to the court and the police and although he had no problem appearing before the board, he had no information which could shed light on the merits of the inquiry.

Information on his ministerial operations, he said, had already been given to the competent authorities and he was not in a position to give the same privileged information in public, moreover, in the presence of lawyers and third parties who had made several attempts to tarnish his “integrity and professionalism”, as well as his political career.

He argued that to safeguard police investigations and magisterial inquiries into the operations of the ministry he had held, it was not wise for information he had given in private to be made public.

But in a decree issued on Thursday evening, the board said Mizzi could opt not to answer any questions he felt would incriminate him. 

The board said it also had the option of hearing part of, or all, his testimony behind closed doors. 

In the decree, the board said Mizzi was wrong to argue the inquiry's mandate was focused purely on Caruana Galizia's assassination. 

The board's mandate also extends to investigating whether there were shortcomings or omissions by the state that could have led to her killing. 

The board said it was also examining whether a culture of impunity had been created that could have played a role in the assassination. 

For this purpose, the board said it was ordering Mizzi to appear before it on Friday morning.

Times of Malta will be reporting live Friday's inquiry