(CNN) A magistrate judge in Brooklyn on Tuesday ordered a man who had been a key witness in special counsel Robert Mueller's investigation and was arrested Monday on federal child pornography charges to be driven by FBI agents to Virginia on Wednesday for his next court appearance.

The man, George Aref Nader, was detained upon his arrival at John F. Kennedy International Airport on Monday for "transporting visual depictions of minors engaged in sexually explicit conduct." He has a serious heart condition, according to his lawyer.

As a result, US Magistrate Judge Cheryl Pollack ordered him to be transported to Virginia, where he was charged, by two FBI agents. One of the agents is a trained paramedic. The arrangement was proposed by the government and Nader consented after his lawyer had initially suggested keeping him under the watch of private security.

Nader will spend the night in a Brooklyn jail on Tuesday before being driven to Virginia on Wednesday.

On Monday, the judge postponed a decision on bail to allow Nader's attorney to gather additional information related to a proposed set of conditions that could accommodate Nader's medical condition.

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