Apple’s association with the United States National Security Agency may once again put the company in the spotlight as Germany begins to investigate the agency’s recent activity. According to a report by The Wall Street Journal, members of a German parliamentary commission want the heads of a number of US-based tech companies, including Apple, to participate in their investigation of the NSA’s involvement in monitoring German officials.

Apple, for its part, has denied direct involvement with PRISM program and repeatedly said it has not allowed the government to have direct access to its servers.

Whether or not Tim Cook will actually attend is uncertain, as the investigative committee’s request does not mandate the company’s participation. The Apple CEO has voluntarily testified before a government hearing in the past to push a message on behalf of the company.

Last year, Tim Cook offered his voice to a Senate hearing investigating how major companies used offshore accounts in relation to US tax requirements; it’s possible he could accept the invitation from the German parliament to push the company’s call for the US government to reform its surveillance strategies.

Tim Cook has also represented Apple in the past in meetings with President Obama to discuss the government’s surveillance programs. As the WSJ notes, Facebook, Google, Microsoft, and Twitter are also included in the German parliamentary committee’s request.