Slaughter and May has filed a $2.16m (£1.6m) High Court claim for unpaid fees against former client Randall Dillard, the founder of now-defunct City investment firm Liongate Capital Management.

The magic circle firm alleges that Dillard failed to pay fees and disbursements for legal services it carried out under a retainer, over a period of almost four years.

Slaughters was first instructed by Dillard in July 2013, when he brought in the firm to act for him in a personal capacity. A retainer was agreed, under which Slaughters provided legal services to Dillard on matters including a partnership dispute, cases in the High Court and the Grand Court of the Cayman Islands, and a regulatory compliance investigation.

Slaughters issued five invoices to Dillard for work carried out between July 2013 and March 2017, and although the firm received partial payments of $100,000 and $99,935 in November 2016 and January 2017 respectively, Slaughters claims Dillard has failed to pay the remaining amount.

Slaughters terminated the retainer in April 2017, and after Dillard did not respond to the firm's final request to pay the outstanding amount, Slaughters combined all outstanding invoices into a single bill with a 20 December 2017 payment deadline,

Slaughters filed its claim for $2.158m at the High Court this January. The firm is also claiming interest accruing at a rate of $147.85 a day, along with statutory interest, and costs of $10,000.

An interim charging order was filed this May, and an application date of 17 July has been set for a decision on whether the charge created by the order should continue.

Slaughters said in a statement: "We confirm that we have filed a commercial contract claim in the Commercial Court against Randall Dillard in relation to outstanding fees owed to the firm. Given proceedings are underway, it would be inappropriate for us to comment further at this point."

Dillard, previously a managing director in the investment banking department at Japanese investment bank Nomura, founded hedge fund Liongate in London in 2003. He sold a large stake in the business to US money manager Principal Global Investors in 2013 before it was closed down in 2015.