Wesselink said: "This will be a little more complicated, but we will not stop doing our work."
The SRJI was founded six years ago. Its lawyers and researchers investigate incidents of detention, torture, enforced disappearances and extrajudicial executions in Chechnya.
It brings cases to the European Court of Human Rights in Strasbourg, France.
In a case earlier this month, the court held Russia responsible for the disappearance of a father and son, and for the murder of a woman whose body was discovered in a mass grave in Chechnya.
Wesselink said the group plans to either appeal the decision or submit a new application.
The SRJI will continue to work out of its headquarters in the Netherlands.