When Reza Zarrab, a wealthy gold trader from Turkey, was in need of a top-flight lawyer after his arrest in March, he hired Benjamin Brafman, one of New York’s most prominent defense lawyers.

Mr. Zarrab did not stop there.

In just four months, he has hired five white-collar law firms to defend him, with 15 lawyers — many of them among the most accomplished in their field — having entered the case on his behalf. A 16th lawyer, from a sixth firm, is joining soon, court papers show.

The team includes Paul D. Clement, the former solicitor general of the United States, and his partner, Viet D. Dinh, a former assistant attorney general, who are both appellate specialists.

There is also William A. Burck, a former White House deputy counsel, and now, among other things, an expert in cases that cross international borders. His clients include FIFA, the ruling body of global soccer, which is currently at the center of a major corruption scandal.