Former partners of collapsed law firm Cobbetts are facing a multimillion pound claim from a former client, who alleges the firm was professionally negligent and engaged in misrepresentation. The news comes as adminstrators KPMG confirmed they would be extending the process to August.

The claim is being brought by Leicestershire-based businessman David Frosdick, who instructed the firm to advise him on losses and injury sustained in a road accident in August 2007.

Frosdick says he was advised total damages could have risen to €18m (£15m), but that after he instructed the firm, Cobbetts failed to properly investigate or recover the losses sustained.

The claimant argues the firm's lack of action amounted to an act of professional negligence and that misrepresentations were made by Cobbetts which induced him to instruct the firm.

Cobbetts' LLP, a large part of which was sold in a pre-pack deal to DWF in February 2013, is currently in administration.

In a separate letter addressed to the administrators KPMG, Frosdick says he intends to make a "substantial contribution to the unsecured creditors" of the collapsed firm, in the event the court finds in his favour.

Frosdick and KPMG are currently awaiting a decision by High Court judge Master Yoxall on whether the claim will be heard.

The claim comes almost a year after Cobbetts entered administration, after its business failed to recover from the impact of the financial crisis, while paying off expensive leases on its offices taken out in 2006 and 2007.

Earlier this month, Legal Week reported that former Cobbetts partners who moved to DWF in last year's pre-pack deal may be asked to partially fund distribution payments to creditors.

Under the terms of the pre-pack purchase agreement, Cobbetts partners who moved to DWF are currently in a two-year lock-in, which if broken could incur a financial penalty of up to £100,000.

Separately, KPMG confirmed it has extended the administration to 5 August.

In a filing on Companies' House, joint administrator Howard Smith confirmed the firm's creditors had given KPMG consent to continue with the administration. The administration would have otherwise automatically concluded in February, a year after the professional services firm was appointed.

Also filed this week was an administrators' progress report for work carried out to 13 December, which shows that the firm's Creditors' Committee has requested KPMG "carry out additional investigations, with a view to additional recoveries for creditors, which have included transcribed interviews with certain members and staff of the LLP".

The administrators also accrued £226,000 time costs in the period from 6 August to 6 December 2013, at an average rate of £361 an hour.