Brazil has made strides in its anti-bribery enforcement efforts, but a working group at the Organization for Economic Cooperation and Development (OECD) is concerned the country doesn’t have the controls in place to sustain its progress.

The OECD working group released a report this month reviewing Brazil’s anti-bribery efforts and what challenges and positive achievements the country has seen. The OECD has been working with Brazilian officials for nearly a decade since its last review, when the country agreed to refine its legal and institutional framework for imposing corporate liability, among other changes.

Those corporate liability actions have seen Brazil use leniency agreements as part of resolutions, like it did with mixed results in the Odebrecht case, and increase cooperation with other international agencies. Brazilian authorities have played a part in recent resolutions with Glencore, Honeywell, and Gol regarding violations of the U.S. Foreign Corrupt Practices Act.

But the OECD group said it is “concerned that Brazil may not be able to sustain the level of foreign bribery enforcement that it achieved in recent years.” It said the country could still better detect and enforce against foreign bribery offenses, citing the slow pace of investigations into allegations of foreign bribery.

“Brazil’s first-ever criminal proceeding for foreign bribery remains ongoing after nearly a decade,” the report noted. “So far, eight of the nine defendants in that case have been acquitted because of the statute of limitations. … The group is seriously concerned that Brazil’s statute of limitations for natural persons remains inadequate to effectively sanction foreign bribery.”

The OECD group also cited Brazil for not properly protecting whistleblowers who raise allegations of foreign bribery and flagged independence issues in the country, including political bias by law enforcement agents in cases.

Among its recommendations, the group said it will look for Brazilian authorities to provide more guidance on how they view aggravating and mitigating factors in cases, update the country’s risk assessment to address the risks of money laundering predicated on foreign bribery, and increase penalty totals where appropriate. The OECD added it would like to see Brazil “urgently” address its apparent statute of limitation issues.

Brazil will submit a written report to the working group in two years regarding its progress.