Two Miss Universe judges have resigned days before the annual beauty pageant, with one of them accusing organisers of rigging the selection process.

Lebanese-French musician Omar Harfouch, who announced his resignation from the eight-member jury on Instagram, alleged that an impromptu jury had pre-selected finalists ahead of the competition, set to be held on Friday in Thailand.

Hours later, French football manager Claude Makélélé also announced he'd pulled out, citing unforeseen personal reasons.

The resignations come just weeks after several Miss Universe contestants walked out of a pre-pageant event over controversial comments made by an official from host nation Thailand.

An impromptu jury has been formed to select 30 finalists from among the 136 participating countries, without the presence of any of the real jury members, including me, Mr Harfouch wrote in an Instagram post on Tuesday, saying he had discovered this via social media.

The unofficial jury comprises individuals with significant potential conflicts of interest due to personal relationships with some contestants, he claimed, though he did not elaborate on how this jury would function.

The Miss Universe Organisation put out a statement rebuffing Harfouch's claims, asserting no external group had been authorized to evaluate delegates or select finalists.

Mr Makélélé described his resignation as a difficult decision and reiterated the values of empowerment and diversity associated with the event.

The pageant faced backlash earlier this month after Thailand's director publicly berated Miss Mexico at a pre-event for not promoting the event on social media, causing several contestants to walk out.