Texas billionaire Allen Stanford and top aides at his investment group failed to respond to recent subpoenas seeking their testimony on what federal investigators now call a massive fraud, court papers said on Tuesday.

The Securities and Exchange Commission said it had issued subpoenas to Stanford, aide James Davis and O.Y. Goswick, a board member of Stanford International Bank. None of these witnesses appeared for testimony or produced a single document, the SEC said.

(Reporting by Randall Mikkelsen, editing by Jackie Frank)