Bloomberg - The U.S. government has interviewed one Schlumberger Ltd. worker and wants access to four other current and former employees as part of a probe into potential sanctions violations in Iran and Sudan, according to federal court documents.

The unnamed worker for the world�s biggest oil-services provider was interviewed on March 8 about a matter related to a company Schlumberger acquired in 2014. That undisclosed company was under investigation by the Justice Department, and Schlumberger later disclosed a potential �matter� related to the International Emergency Economic Powers Act, according to filings.

Schlumberger �understands that the government remains interested in interviewing two current company employees and two former company employees,� according to an April 1 federal court filing by the company in Washington D.C. �The company is committed to continuing to work with counsel for the employees, where applicable, to schedule these interviews according to the government�s preferences.�

In 2015, Schlumberger pleaded guilty to sanctions violations in Iran and Sudan and was put on three-year probation. That probation was extended for another year so the government could investigate whether the company violated terms of its plea agreement. The Financial Times first reported that the government interviewed a Schlumberger worker.

Schlumberger has said in court filings it voluntarily reported four separate matters related to the Powers Act over the past two years, including the issue related to the company it acquired in 2014. Joao Felix, a spokesman for Schlumberger, declined to comment beyond the company�s most recent court filings.

�The company provided detail to the government regarding the substantial remediation it has undertaken in response to lessons learned from its investigation of the matters,� Schlumberger said in this week�s filing. It expects the term of the probation to expire at the end of this month �without issue.�