Later he expanded to the building sector, establishing his company Bang Saen Maha Nakhon.
This spurred the rise of his economic and political influence which he, in turn, used to provide for a further boost of the urban and industrial development of his home province.
By financially supporting parties and candidates, he controlled up to 20 seats in the Thai House of Representatives.
[5] Somchai, together with local councillor Passakorn Homhuan, was charged with the premeditated murder of Prayoon Sithichote, headman of a neighbouring sub-district, through hired killers in 2003.
Pending appeal proceedings, Somchai was set free on terms of a ten million baht bail.
He was also convicted in a corruption case in connection with the construction of a garbage dump, for which he was sentenced to five years and four months in jail.
Somchai was the father of Sontaya Kunplome,[10] leader of the Phalang Chon Party, president of Pattaya United F.C., minister of culture under Yingluck Shinawatra and former tourism minister under Thaksin Shinawatra, Wittaya Khunpluem, president of Chonburi F.C., chairman of the provincial administrative council of Chonburi and Member of Parliament representing Chonburi, Itthiphol Khunpluem, mayor of Pattaya and Narongchai Khunpleum, Mayor of Saensuk Municipality.