Linklaters is being sued by former Arsenal Football Club shareholder Lady Nina Bracewell-Smith, according to court documents filed this summer.

According to the documents, filed at London's Commercial Court on 31 July, Bracewell-Smith – who until 2011 owned a 15.9% stake in Arsenal – has brought a professional negligence claim against Linklaters and big four accountant Deloitte.

West End firm Gordon Dadds is acting for Bracewell-Smith, according to the claim document, which contains no more detail of the specifics of the claim.

Bracewell-Smith's reasons for bringing the claim are unclear, although Linklaters advised her on the 2011 sale of her shares in Arsenal to Kroenke Sports Enterprises, the company controlled by US businessman Stan Kroenke, now the Premier League club's majority shareholder.

On the 2011 deal, private equity partner Ian Bagshaw led the Linklaters team acting for Bracewell-Smith. He has since moved to US firm White & Case, where he is now global co-head of private equity.

Arsenal's regular lawyers at Slaughter and May acted for the club on the share sale, while Clifford Chance advised Kroenke.

Two years after selling her stake in Arsenal, Bracewell-Smith said that she "deeply" regretted selling to Kroenke, in tweets which have since been deleted.

In 2014 she fought a High Court dispute with Alistair Barclay, son of Telegraph Group owner Sir David Barclay, in connection with the sale of her stake in Arsenal for a reported £116m and her subsequent move to Monaco.

Linklaters and Deloitte declined to comment. Gordon Dadds was contacted for comment.