Portuguese authorities have raided Benfica facilities as part of an operation to investigate corruption allegations involving club officials.
The club say they are fully cooperating with local officials.
The raid came as Portuguese media said Benfica legal adviser Paulo Goncalves was detained after being accused of obstruction of justice.
The club says it is confident that Goncalves will be allowed to prove his innocence during the judicial process.
Prosecutors earlier this year named Benfica president Luis Filipe Vieira in an investigation into a corruption scheme that allegedly allowed officials illegal access to judicial documents.