This article in The Independent looks at Parliaments ancient powers to prosecute liars and those in contempt, last used in the 1880s. There have been new calls to employ such powers after witnesses provided contrary evidence to Parliamentary Inquiries.
"In the US anyone found in contempt of a Senate or House Committee can be reported to the US Attorney..."
For Interactive Democracy I propose much wider sanctions against lying in public life to keep public debate clean. This could be operated in a similar way to the Advertising Standards Authority, which responds to public complaints. It could have legal powers to investigate deceit and use a variety of powers, everything from a public warning to jail.