The teeth of Article 21 of the Code of Civil Procedure: evidential sanctions for breach of the duty of truthfulness

Any party bringing proceedings must present the relevant facts fully and truthfully. In the event of a breach of Article 21 of the Code of Civil Procedure, the court may draw whatever conclusion it deems appropriate. This may go beyond an order to pay costs: a new round of evidence may also be refused.

The case: the claimant lies about his involvement

Supreme Court 18 September 2026, ECLI:NL:HR:2026:1500, concerns proceedings for damages arising from a breach of a non-competition clause in the maritime towage sector. The former director of Fairmount, who was subject to the non-competition clause, was accused of having been involved in the establishment of a competing company (named ALP) and that, had ALP not been established, a partnership between Fairmount and a particular shipowner would have been formed. A claim was made for payment of a fine and damages on the grounds that this partnership had not materialised.

The former director of Fairmount, the appellant in the appeal in cassation, had stated under oath during the proceedings that, since his departure, he had “not been involved in any way with the maritime towage sector or ALP, and had never spoken to or visited any of Fairmount’s business associates”. Nevertheless, it transpired that he had played a significant role in the collaboration between ALP and a shipowner.

What evidence was refused?

He wished to provide evidence to rebut the preliminary finding that Fairmount would have collaborated with that shipowner even without the establishment of ALP. To this end, he offered, amongst other things, witness evidence regarding Fairmount’s lack of interest in collaboration. The Court of Appeal refused to allow further evidence to be adduced. The Court of Appeal cited several reasons for this, including his lies. According to the Supreme Court, the lying constituted an independent ground. The Supreme Court upheld that sanction.

Previous case involving a severe sanction for lying

This is not an isolated incident. In a 2017 case, the court dismissed claims on the grounds of a breach of the duty of truthfulness. A key factor in the proceedings was the role played by one of the claimants in the cannabis cultivation operation in the warehouse. The claimants argued in the proceedings that they were not personally involved in the cultivation operation. A subsequent criminal case later revealed that one of the claimants had actually set up the cultivation operation himself. He had therefore lied. In 2021, the Supreme Court also upheld in this case the sanction imposed by the court for breaching Article 21 of the Code of Civil Procedure (Supreme Court 16 July 2021, ECLI:NL:HR:2021:1144).

The (costly) lesson

Anyone who misinforms the court risks not only their credibility but also a substantial opportunity to prove their case.

In the case involving the maritime towage companies, it was a costly lesson: Fairmount claimed damages of USD 51,203.00. The Court awarded USD 6,862,287.

Questions?

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