It is OK to sell leather products with raw materials from pig. However, the market will be limited to a smaller group of potential customers only.
Most of the Malaysians (especially Malays) are Muslims. They could not touch / eat products related to pig.
Your friend can still sell pig's productes to those non-Muslims, such as Chinese. But they are less than 30% of the population. The potential customer base is less tham 3 millions.