Majlis Permuafakatan Felda's Mazlan Aliman urges the government to treat the ex-director fairly.
Mazlan Aliman says Felda has failed to pay subsistence allowances to some 31,000 settlers.
His arrest comes after a police report was lodged by Rosmah Mansor's lawyer.
They want Anak chairperson to be released from police detention immediately.
UPDATED 5.38PM | Mazlan Aliman is also Amanah supreme council member.
Police report lodged amid fear that the programme will stir up dissatisfaction among the settlers.
They particularly take issue on incentive on replantation debts, which they say doesn't address main problems.
Anak’s Mazlan Aliman recalls when critics protested the listing of FGV, the PM took offence.
Two groups will bring anti-corruption agenda to Felda settlers, starting with the Pekan constituency.
'Raising the issue of Felda's name is petty and distracts from the key issues.'
The Umno-turned-Bersatu member shares concern over Felda's woes with Amanah man.
Statutory bodies such as KWAP, LTAT, Tabung Haji and Perkeso are still holding on to their stake in troubled FGV.