Ampang PKR said its Youth chief Adam Rosly, who was arrested for corruption last week, fulfilled his duties in the elected party position with integrity.
"He won the Ampang PKR Youth chief post legitimately through the party election in 2014.
"He fulfilled his duties well and always co-operated with the Ampang MP (Zuraida Kamaruddin).
"He is also someone with high integrity when it came to fulfilling his duties as Ampang PKR Youth chief," Ampang PKR secretary Sabri Abu Bakar said in a statement.
Sabri also clarified that Adam, 28, is not special officer to Selangor Menteri Besar Azmin Ali or Zuraida, as earlier reported.
He also does not hold any state political appoinments including on the local council, Sabri said.
Sabri urged the MACC to conduct the investigations professionally.
"We uphold the principle of innocent before proven guilty," he said.
Adam, who has a Datuk title, was detained by the Malaysian Anti-Corruption Commission (MACC) on Thursday after his statement was recorded.
His wealth became a focal point late last year, when Sungai Besar Umno division chief Jamal Md Yunos took journalists on a helicopter ride for an aerial view of the PKR man's castle-like bungalow.
Following this, Adam claimed that he was able to afford the house because he is a successful businessman.