Sun Microsystems said it may have broken anti-bribery laws due to some of its activity outside the US.
If the company is found to have broken these laws it could face heavy fines and be barred from working with the US government, where it has a lot of contracts.
The software company is currently being acquired by Oracle but the revelation introduces some uncertainty.
Alcatel-Lucent had to pay a $2.5m fine because Lucent had broken these laws before it was acquired it in 2006. Lucent had illegally paid for trips for potential customers in China.
Oracle, which is buying Sun Microsystems for more than $7bn said it found out about the situation before signing its agreement to buy Sun.
According to Reuters, Sun said in a filing with the US Securities and Exchange Commission, "We have identified potential violations of the Foreign Corrupt Practices Act, the resolution of which could possibly have a material effect on our business.
"The outcome of these, or any future matters, cannot be predicted."
Sun's acquisition by Oracle will give it access to strategically important Java and Solaris technologies, which underpin the Oracle database.
"Oracle will be the only company that can engineer an integrated system - applications to disc - where all the pieces fit and work together so customers do not have to do it themselves. Our customers benefit, as their systems integration costs go down while system performance, reliability and security go up," said Oracle CEO Larry Ellison.