Senator Richard Gordon on Wednesday demanded that the Commission on Human Rights (CHR) issue an apology before it can attend the resumption of the Senate probe on alleged extra-judicial killings.

"Mag-apologize muna sila [They should apologize first]," Gordon, chair of the Senate justice committee, told reporters ahead of the panel's hearing on Thursday.

One of the commissioners of the CHR, Roberto Eugenio Cadiz, had earlier criticized Gordon for briefly suspending the committee probe following tensions between him and Senator Leila de Lima, who was stripped of the panel chairmanship.

• De Lima ousted as Senate justice committee chair

Cadiz accused him of being a coward and said he should not be afraid to conduct the hearing.

Gordon, however, is now commencing with the probe.

CHR chair Chito Gascon had already called Gordon and apologized but the lawmaker said he is not satisfied.

"It should be the CHR that should apologize and should castigate Cadiz," said Gordon.