The cost of oldco Rangers' liquidation process has risen by almost £2.2m since April last year, it has been revealed.

The figures were revealed in the most recent report to creditors by liquidators BDO and show the price of the process, which began in October 2012, has risen from £10.8m to £12.95m in the 15 months since the firm's last report.

Legal fees as well as the cost of litigation in relation to the process, now ongoing for almost four years, has reached £7.8m and increased by more than £886,000 since April last year.

The figures in the report also revealed BDO has received £2.9m since Ranger went into liquidation - and almost £800,000 since April 2015.

The increase in the cost of the liquidation process since the last BDO report means a blow to creditors with the pot dropping from £18.8m to £16.7m.

The majority of legal costs (£5.4m) were paid to London lawyer firm Stephenson Harwood in relation to the settlement of a legal claim against another lawyers firm Collyer Bristow over the acquisition of of oldco Rangers by Craig Whyte.

BDO's report states: "This is a complex liquidation containing a number of key areas of investigation, each of which may have a significant impact on the ultimate outcome for creditors.

"However, due to the highly sensitive nature of certain aspects of these investigations, we consider that it is not appropriate to provide full details in respect of our investigations to date in this circular."

BDO has been involved in a catalogue of legal cases since the liquidation process began in October 2012.

In its last report, BDO advised the joint liquidators had been notified of a potential claim by solicitors representing a firm called Law Financial Limited (LFL), which is 100% owned by Worthington Group and of which Craig Whyte was a former director.

LFL said in this claim it had taken part of the floating charge and the debt due to Lloyds and that it had a secured claim of around £25m in priority to all other creditors.

The joint liquidators then made an application to court in a bid to to set a deadline by which LFL had to submit its formal claim.

The firm, as a result, confirmed it would not be submitting a formal claim in the liquidation.

However, in September 2015, the liquidators then received notice from The Rangers FC Group Limited - a company previously known as Wavetower Limited - confirming it had also taken part of the floating charge and debt due to Lloyds and had a secured claim of £18m.

The legal move was then abandoned by lawyers acting for Wavetower and a new claim for £3m has been submitted, which is still under consideration.

The BDO report says on the matter: "A claim at this level would not preclude the joint liquidators from paying a first dividend to unsecured creditors.

"As a result, once the Wavetower position has been established, the intention of the joint liquidators will be to present an amended scheme of division to the committee with a view to the payment of a first dividend later this year."

Around £72m of the £94.4m owed to the taxman, the biggest creditor, relates to Rangers' use of EBTs. This is known as the so-called Big Tax Case and is still ongoing.

The case is due to be heard at the Supreme Court in London next year.