A rights group has welcomed the voluntary withdrawal of former Bukit Aman Legal Unit chief Mokhtar Mohd Noor from the special taskforce to probe the disappearances of pastor Raymond Koh and activist Amri Che Mat.

Citizens Against Enforced Disappearances (Caged) said, however, that the withdrawal only satisfies one of several demands the group made to improve investigations.

"Caged is glad to put on record that Home Minister Muhyiddin Yassin has indeed responded to some public feedback," spokesperson Rama Ramanathan said in a statement today.

"However, we must emphasise that we consider today’s announcement as no more than a first step towards a taskforce which not only 'sounds like', but is also 'identical with' the recommendations of Suhakam and previous good practices."

Among others, Caged's demands include expanding the taskforce's terms of reference beyond probing the Suhakam report into Koh and Amri's disappearances.

The Suhakam report was released on April 3 following an 18-month inquiry into a series of missing person cases.

"Based on the terms of reference, the composition and authority of the taskforce must be completely revamped," said the Caged spokesperson, who also urged the remaining five taskforce members to follow Mokhtar's lead and withdraw from their positions.

Moving forward, Rama said investigators from the taskforce should conduct an honest, thorough and well-resourced investigation, unlike the "slipshod and erratic police investigations to date in both cases."

He also called for the taskforce to probe police personnel who Suhakam believes should be investigated for allegedly falsifying, planting and withholding evidence.

"This requires review of Suhakam Inquiry’s notes of proceedings," he added.

With regards to Koh's case, Rama said the taskforce should proceed with its probe despite the ongoing related criminal trial against his alleged kidnapper, former part-time Uber driver Lam Chang Nam.

"Drop the pretence that the Koh investigation must be put on ice because someone has been charged."

"This is because no one who has read the verbatim notes of proceedings believes the accused person (Lam) can be credibly charged with kidnap or abduction."

Muhyiddin previously said that the taskforce would first begin probing Amri's case, as they need to wait until the criminal case concerning Koh is concluded in court.