A man who said he was hired to record the advisers' conversations may testify before a Federal grand jury investigating their role.
Last fall, Montgomery testified before a federal grand jury investigating Balco.
He was testifying before a House subcommittee investigating political favoritism in the distribution of housing funds.
The executive was testifying before a special parliamentary committee investigating financial scandals in Japan.
More than a dozen athletes testified before the grand jury investigating the company.
Sheffield was one of several athletes who testified before the grand jury investigating Balco.
Last week she testified before a grand jury investigating the case.
The first occasion was in early 1958, when he testified before a special New York state grand jury investigating labor racketeering.
The Chevrolet deal comes less than a week after baseball officials, current players and former stars testified before a House committee investigating steroid use.
Some of the members testified before the grand jury investigating the shooting.