Egypt has strongly criticised the UK for "not helping enough" with the recovery of Egyptian assets frozen since last year.
"UK Treasury is neither helping nor co-operating enough with us to repatriate the frozen assets," an Egyptian senior judicial official told BBC Arabic.
The Treasury's Asset Freezing Unit froze about £85m worth of Egyptian assets 13 months ago.
It denied the Egyptian claims that it was not co-operating.
Assem Algouhary, head of Illicit Gains Department in the Egyptian ministry of justice, accused the Treasury of violating the United Nations Convention against Corruption and a European Union regulation about freezing the assets.
This is first time Egypt has criticised British authorities publicly over the issue.
The UK took the lead in the EU to issue legislation to freeze the assets of 19 Egyptians, including former President Hosni Mubarak, his family members and some of his former ministers during the Egyptian uprising early last year.
'One option left'
Mr Algouhary said he received an official letter from the Treasury last December "confirming that it cannot give any information about the frozen assets or persons who own it".
"We have been left with only one option which is to take judicial proceedings to get a court order to enforce the British to give us information we need for recovery of the monies," Mr Algouhary told BBC.
"Egypt filed a lawsuit in the UK's high administrative court against the UK Treasury last March," he revealed.
The UK has been under fire from Egyptian media which held London responsible for not repatriating the frozen assets.
But the Egyptian media started to criticise the Egyptian government after the Foreign and Commonwealth Office revealed that Egyptian officials cancelled a meeting planned at the end of last December to discuss ways to recover the assets.
The Treasury denied Egyptian allegations of not co-operating.
"We are co-operating with the Egyptians within the British laws," a spokesman told BBC Arabic.
No power to repatriate
He refused to comment on any judicial proceedings taken by the Egyptian government.
However, the spokesman emphasised the UK's pledge to help Egypt as much as possible within its laws and regulations.
"The Treasury is only responsible for freezing assets and does not have the power or authority to repatriate it," he added.
The spokesman refused to comment on Egyptian claims that it violated UN or EU regulations.
Some Egyptian MPs have voiced their concern over the reasons why the government could not recover the frozen assets from UK.
They insist that the justice and foreign ministers appear before parliament to answer the accusations of not doing enough to recover the frozen assets.