The problem happened in the connection between the federal prison in Terre Haute, Ind., where the execution took place, and Oklahoma City.
About 300 survivors and relatives of victims of the April 19, 1995, blast that killed 168 people in the Alfred P. Murrah Federal Building in the Oklahoma capital watched the execution of McVeigh on closed-circuit television.
"The connection did not initially go live, and they had to work out whatever the issues were," said Clarence Cranford Jr., a public information officer at the Terre Haute facility.
Cranford could not say what caused the glitch and did not know if it resulted from outside interference.
The execution took center stage in a debate this spring over First Amendment rights when Internet company Entertainment Network sought permission to Webcast the death-chamber scene. In April, however, a federal judge ruled that the Federal Bureau of Prisons' policy on broadcasting of the execution did not violate the company's free-speech rights.
The broadcast was wired from the prison to Oklahoma in an encrypted feed to prevent interception.
Despite the technical mishap with the broadcast, the execution by lethal injection proceeded as planned, and McVeigh was pronounced dead at 5:14 a.m. PDT.