Washington, April 28: A federal judge in Washington has dismissed former Donald Trump campaign chairman Paul Manafort’s civil suit challenging the authority of Special Counsel Robert Mueller over the on-going Russia probe. “A civil case is not the appropriate vehicle for taking issue with what a prosecutor has done in the past or where he might be headed in the future,” wrote US District Judge Amy Berman Jackson in the ruling on Friday, Xinhua news agency reported. “It is a sound and well-established principle that a court should not exercise its equitable powers to interfere with or enjoin an ongoing criminal investigation when the defendant will have the opportunity to challenge any defect in the prosecution in the trial court or on direct appeal,” Jackson wrote, “therefore, the Court finds that this civil complaint must be dismissed.”