Complex sentence: Initially centering on Napoles'involvement in the 2004 Fertilizer Fund scam, the government investigation on Luy's testimony has since expanded to cover Napoles' involvement in a wider scam involving the misuse of PDAF funds from 2003 to 2013.
Split into simpler sentences: Initially centering on Napoles'involvement in the 2004 Fertilizer Fund scam. The government investigation on Luy's testimony has since expanded to cover Napoles' involvement in a wider scam involving the misuse of PDAF funds from 2003 to 2013.