A law firm that collapsed suddenly is being investigated over a "sophisticated suspected fraud" involving the "improper removal and misuse" of £39.5m of client funds, a regulator has said.

Sheffield-based PM Law Ltd, which had 25 offices in Yorkshire, Cumbria, Berkshire, Derbyshire and London, shut on 2 February, leaving hundreds of people out of work and tens of thousands of cases affected.

The Solicitors Regulation Authority (SRA), which intervened after the closure, said it estimated more than £21m of claims had been made to its compensation fund to date.

The BBC has repeatedly contacted PM Law Ltd, which entered voluntary liquidation on 3 March, for comment but has received no response.

The PM Law group consisted of 11 companies, 25 offices and over 30 trading names, and included firms such as Proddow Mackay, Butterworths Solicitors and WB Pennine Solicitors.

It specialised in personal injury, wills and conveyancing and, according to its website, employed over 600 members of staff.

The SRA said the intervention into PM Law had been one of the largest and most complex it had ever undertaken, involving 25,000 emails and letters and 17,000 inquiries.

Paul Hastings, the SRA's director of client protection, said: "We are continuing to do all we can to support former clients of PM Law, including by reuniting them with their money or files.

"Many of the former clients faced significant upheaval at a stressful time, so we have been determined to provide as much support as possible."

According to the regulator, as of 17 April, 92 claims totalling £9.31m had been paid to former clients from the SRA Compensation Fund.

A further £6.8m had been paid out from money held within the firm at the time the SRA intervened, meanwhile 9,300 files had been returned to clients, the regulator said.

Clients of PM Law who previously spoke to the BBC said they had been in the middle of buying or selling a home, were facing the risk of collapsed moves, or losing their deposits due to the firm's sudden closure.

Staff were also left devastated, discovering they had lost their jobs via a notice posted in the windows of the company's premises.

Further details on how clients are being supported are available on the SRA's website.

Report Fraud, a nationwide service run by City of London Police, previously said it was aware of the fraud allegations involving PM Law.

A Report Fraud spokesperson said at the time it had "received reports in connection to these allegations" and was liaising with the SRA.

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