The Delhi High Court today asked Himachal Pradesh Chief Minister Virbhadra Singh, an accused in a disproportionate assets case ,to join the probe in the matter and directed CBI not to arrest him. Justice Pratibha Rani said this after Singh told the court that he was willing to join the investigation and cooperate with the agency.<br/><br/>The court decision came while disposing of CBI's plea seeking vacation of Himachal Pradesh High Court's interim order restraining the agency from arresting, interrogating or filing a charge sheet against Virabhadra Singh in the case. The CBI had yesterday told the court that investigation in the case was seriously held up due to the interim order.