Prominent former civil servants group G25 has joined the call for the High Court judge in former prime minister Najib Abdul Razak's corruption cases to recuse himself from further hearing the case.

In a statement today, G25 said it wholeheartedly supports the call by Bar Council president George Varughese to have justice Mohd Sofian Abdul Razak withdraw from presiding the case.

"This is because of the failure of the judge to disclose the fact that his brother, Mohd Soffi Abdul Razak, is a member of Umno, and the Pahang state executive councillor, as well as the assemblyperson for the Pahang state constituency of Benta.

"Given that the former prime minister was until recently the president of Umno and chairperson of BN, and is himself a Pahang MP, the judge ought to have disclosed his relationship to his brother and the latter’s position in Umno and the state government to the prosecution and the defence prior to the hearing," said G25.

"Judicial precedents have established that a judge must disclose any kind of connection in a case before him to all parties at the outset, and should let the parties decide whether to ask him to recuse or not," added G25.

"The judge in this case did not do so. With respect, we are of the view that this is highly inappropriate," said group.

It is trite law that justice must not only be done, but also seen to be done, said G25.

"We align ourselves with the reasons eloquently elucidated by the Bar Council president for the judge to recuse himself from this high profile case," said G25.

On July 4, Najib was charged with three counts of criminal breach of trust and one charge of abuse of power in relation to the RM42 million in his personal bank account, believed to have originated from former 1MDB subsidiary SRC International.

Attorney-general and lead prosecutor to the case Tommy Thomas, had claimed he had no knowledge of the judge's Umno links prior to the case being brought to court.

Mohd Soffi is a five-term Umno assemblyperson and four-time state executive councillor member.