Under dispute was whether the commission could amend complaints referrals it sent to the Competition Tribunal or whether a new complaint had to be lodged every time a new party or conduct was uncovered in its investigations.

The commission originally started investigating three separate claims of price fixing and collusion in September 2007 by manufacturers and sellers of flexible polyurethane foam, Loungefoam, Vitafoam and Feltex.

After investigations, it wanted to include Steinhoff Africa in the complaints referral and expand charges to Steinhoff International, Feltex and Kap.

In 2010, the tribunal granted the commission's request to change the complaints referral. This decision was, however, overturned by the CAC in May 2011.

In February this year, the commission submitted that the Competition Act did not define the term "complaint" nor require that the parties believed to be implicated, as well as prohibited practices, be mentioned in the complaint.

It said the act could be interpreted broadly and inclusively.

It contended that the act allowed it to add particulars to its referral and, therefore, that claims that were not in the original complaint could be included in the referral.

The respondents submitted that the referral was confined to the facts and allegations in the original complaint and the parties mentioned in it.

The commission had applied to the CAC for leave to appeal its decision, which was pending, but had since approached the Constitutional Court on the basis that faith needed to be restored in the commission's role and powers.

The parties were expected to address whether the commission was entitled to approach the Constitutional Court directly.