The controversial former bank chief Sir Fred Goodwin is the latest high profile figure to obtain a superinjunction, it has emerged.

The existence of the measure – which bans the press from reporting that an injunction has been obtained – can be revealed after a backbench Liberal Democrat, John Hemming, raised the issue in the Commons.

"In a secret hearing this week Fred Goodwin has obtained a superinjunction preventing him being identified as a banker," said Hemming, the MP for Birmingham Yardley.

Hemming, who used parliamentary privilege to avoid the legal ban on reporting the use of superinjunctions, asked: "Will the government have a debate or a statement on freedom of speech and whether there's one rule for the rich like Fred Goodwin and one rule for the poor?"

Goodwin, who presided over the near collapse of the Royal Bank of Scotland, was reported to have been angered by press coverage after he became popularly known as "Fred the Shred".

He attracted widespread media attention after he was forced to step down in 2008 as a non-negotiable condition of the bank's £20bn bailout by the taxpayer. Goodwin initially left RBS with a pension of £700,000 a year and a lump sum of nearly £3m. He agreed to reduce the payout following public outcry.

News that Goodwin has obtained a superinjunction – over issues that cannot be reported – has raised further questions about the use of the measures.

Last year an outcry prompted the judiciary to establish a committee – chaired by the master of the rolls, Lord Neuberger – to investigate superinjunctions. The committee, which includes judges, lawyers and experts from the press, is expected to deliver its findings before Easter.

Hemming's decision to use parliamentary privilege follows increasing frustration amongst MPs at the willingness of the courts to continue granting superinjunctions.

The ability of parliamentary privilege to circumvent them was established in 2009 when a Labour MP, Paul Farrelly, took similar steps to reveal the existence of a superinjunction obtained by the oil trading firm Trafigura gagging the Guardian over its reporting of the dumping of toxic waste being in Ivory Coast.