At first I thought this was the Monarch Butterfly (Danaus plexippus), but if you look closely, the Monarch butterfly's wings are primarily orange. This butterfly's wings are orange on the upper side and white at the bottom. After a lot of searching on Google, I finally found the name of this butterfly - The Malay Tiger or Mangrove Butterfly (Danaus affinis malayanus). This butterfly is a species from the sub-family of milkweed butterflies, Danainae. It is usually found near mangrove areas. Apparently this is an endangered species and can usually be found at 2 locations in Malaysia, Kuala Selangor Nature Park and Kuala Kurau, Perak.
Somehow, this Malay Tiger Butterfly managed to find its way to our garden. We found it perched on an aster flower plant (daisy).
Malay Tiger Butterfly on White Daisy