An MP has been accused of potentially causing "significant and lasting damage" to the reputation of a tech company's directors.
David Davies suggested at the Welsh Affairs Committee that Blurrt bosses may have taken £179,000 of public cash.
But Mr Davies was wrong and Nick Miller, the firm's chairman, has demanded an "immediate public apology".
In response, the MP invited Mr Miller to discuss S4C's investment in the firm at the committee, which he chairs.
S4C's commercial arm took a 22% stake in Blurrt in 2014.
Blurrt, which was given £770,000 in public money, closed its only office in Wales in July and four people lost their jobs.
The Welsh language channel has now restructured its commercial arm, including appointing chief executive Owen Evans as chairman of the board of the body, known as SDML.
In December, S4C executives appeared in front of the Welsh Affairs Select Committee.
Questioning the channel's bosses, Conservative MP for Monmouth Mr Davies said the most recent accounts appeared to show "£179,000 being paid to the directors" of Blurrt, saying the cash looked like loans to the directors.
He speculated in the meeting, with the company making no sales, whether "the money they are being paid is simply public funds, including funds from S4C".
In a letter to Mr Davies in January, recently published on Parliament's website, Mr Miller said "categorically... this was not the case" adding it appeared to arise from his "inability to understand basic company accounts".
Mr Miller said the Monmouth MP referred to "directors' loans on the accounts, which he clearly believes are loans to directors".
He added: "In fact they are the opposite and the £180,000 was put into the company by myself and one other director as a means of protecting shareholder interests, including the investments made by SDML.
"This payment was made in the form of unsecured loans to prevent Blurrt from entering administration after institutional investors (including SDML) had taken the decision not to invest further.
"Neither of the core directors has ever taken any remuneration from the business."
The letter goes on to say that making this assertion in a televised committee had "potentially caused significant and lasting damage to the reputation of said directors".
Mr Davies said: "Nick Miller was not happy with the line of questioning towards S4C a couple of months ago.
"He has asked for an apology and I have invited him to appear in front of the committee do discuss what happened to S4C's investment in Blurrt."