A spokeswoman for Samsung C&T -- one of the group's biggest subsidiaries -- confirmed about 10 investigators were searching its construction headquarters in Seoul's southern suburbs.
"The company is suspected of diverting billions of won (millions of dollars) of company funds to pay for remodelling and repair expenses of Chairman Lee Kun-Hee's private residence", a detective told AFP.
Lee Kun-Hee has been bedridden since suffering a heart attack in 2014.
His son and heir Lee Jae-Yong was convicted in August of funnelling millions of dollars to ousted president Park Geun- Hye's secret confidante Choi Soon-Sil in return for government favours, and sentenced to five years in prison.
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But even if convicted, many see their sentences significantly reduced on appeal or suspended, leaving only a few actually spending significant time behind bars.
Separately, police have also been investigating allegations that the chairman of Korean Air owner Hanjin Group, Cho Yang-Ho, also diverted company funds to remodel his own house.
Police uncovered both the alleged irregularities while investigating a renowned interior design company over tax avoidance.
Local news reports said more probes into other conglomerates suspected of similar wrongdoings through the same firm were expected.