Ampang Puteri Umno chief Haslinda Mohd Zerain died of a heart attack Wednesday at her Taman Sri Ukay home here.
Haslinda, 37, who was single and the eldest of three siblings, died at 11.35am in the living room of the house while she having a nap on a sofa.
Her mother, Datin Rahimah Abdullah, realised that she was dead when she wanted to wake her up.
Haslinda was buried at the Hulu Klang Muslim Cemetery just before the "asar" (late afternoon) prayers.
Haslinda's younger brother, Mohd Afdan, 33, said his sister had a history of heart ailment and had been discharged three weeks ago from the National Heart Institute where she had undergone treatment for a month.
"Her heart condition was detected five years ago. Her health deteriorated over the last two weeks," he said.
Haslinda's father, Datuk Dr Zerain Abdul Majid, 60, said his daughter had remained at home after her health worsened.
Selangor Umno Liaison Committee deputy chairman Datuk Noh Omar, who paid his last respects, described Haslinda's death as a big loss to the party.
The Agriculture and Agro-based Industry Minister said Haslinda had been active, hardworking and committed in carrying out her duties.
"All of us in Selangor Umno will deeply miss a committed and exemplary leader who had placed the party's interest above hers," he said.
Ampang Umno chief Datuk Ismail Kijo said Haslinda's death came as a shock to Selangor Umno.
"Ampang Umno and Ampang Puteri Umno have lost a leader with potential. It was Haslinda's idea to set up Ampang Puteri Umno," he said.
Besides having been active in politics, Haslinda had been involved in social work.
She contested the Bukit Antarabangsa state seat on a Barisan Nasional (BN) ticket in the 2008 general election but lost to Mohamed Azmin Ali of Parti Keadilan Rakyat (PKR).