MOSCOW - Special riot police secured the perimeter of Moscow's Lefortovo prison on Thursday, and a gaggle of TV cameras and photographers jostled for the best position as the world braced for what could be the largest spy swap since the Cold War.

A convoy of armored vehicles arrived in the morning at the prison, thought to be the central gathering point for people convicted of spying for the West, including nuclear researcher Igor Sutyagin, serving a 14-year sentence for spying for the United States.

Sutyagin's brother and lawyer say he was transferred to Lefortovo earlier this week to take part in the swap and could be flown out to freedom as early as Thursday night. They said Sutyagin saw a list of 11 prisoners in Russia who are being traded for 10 people arrested in the United States for being unregistered Russian agents.