"No charges have been filed against Mr Ong," the company Hotel Properties Ltd said in a statement, adding that Ong has been given a notice of arrest and posted bail of S$100,000 ($75,843.76).
The company added that Ong was asked by the Corrupt Practices Investigation Bureau (CPIB) to provide information on his interactions with transport minister S Iswaran.
Contacted by Reuters the CPIB said it had no immediate comment on the issue.
Shares in Hotel Properties were down 4.4% on the news.
The case, about which the CPIB has provided few details, is a rare high-level probe in a country that prides itself on a government free from corruption.
Prime Minister Lee Hsien Loong on Wednesday said he had instructed Iswaran to take leave of absence until the investigations were completed.