The body representing Scotland's independent lawyers called to the Bar claims the potential loss of measures such as the European Arrest Warrant (EAW) could hamper the investigation and prosecution of serious crime in Scotland.
The UK Government has revealed it is minded to opt-out of the Brussels-imposed powers with the possibility of opting back in at a later date.
However, the faculty claims this would be a potentially expensive exercise which could lead to the UK becoming a safe haven for criminals from throughout the EU.
The legal group has made its position clear to a sub-committee of the House of Lords Select Committee on the European Union, which is carrying out an inquiry into the Government's announcement.
James Wolffe, QC, convener of the Faculty's Law Reform Committee, said: "In a world where people and capital can move freely across borders, it is essential there are good and sound measures for co-operation in the operation of the criminal justice system. It is worth recalling that in the United Kingdom we have had a common market for a little over 300 years.
"With that has come the necessity for close mutual co-operation between the criminal justice jurisdictions of the United Kingdom in the investigation and prosecution of crime. It seems to me that the one comes with the other. The short point is the United Kingdom should not be a safe haven for criminals."
The faculty believes the measures aim to assist domestic criminal justice systems rather than harmonise European police and criminal justice procedures.
A spokesman said: "The European Arrest Warrant has proved to be a highly effective vehicle for the delivery of suspected criminals; both those who have fled this country and those from abroad who have sought refuge here.
"The absence of such a mechanism would, inevitably, result in the UK encountering greater difficulty in repatriating suspects from abroad.
"Worse still, the UK could become something of a bolt-hole for criminals engaged in organised crime or terrorism."
The advocates fear more problems could arise with the loss of access to vital databases and shared intelligence gathering resources – which could include the European Criminal Record Information System (ECRIS).
It said it accepted some of the 130 EU measures put forward were redundant. However, in its written statement to the committee, it stated: "The Government must explain the thinking behind its desire to jettison useful measures such as the EAW – to the undoubted detriment of the UK's policing and criminal justice – for the sake of clearing out obsolete or ineffective measures."
Figures show between 60 and 70 people were returned to Scotland under a European Arrest Warrant between the beginning of 2004 and October 2012.
One of them was Moira Jones's murderer Marek Harcar, who fled to Slovakia after killing the 40-year-old in Glasgow.
Moira's mother, Beatrice Jones, has since been campaigning to have the measures retained in the UK – particularly the ECRIS.
After the Government revealed it was minded to opt-out, she said: "After Harcar was found guilty at the High Court in Glasgow, the Lord Advocate read out his criminal record, which included 13 previous convictions, at least four of them for violence. I was appalled to learn it was the norm for EU citizens to come in unchecked.
"Since then I have met two home secretaries and written hundreds of letters to ministers, MPs and MEPs in my attempts to have changes made in the law so that other families' lives are not torn apart like ours."
A Government spokeswoman said no final decision had been taken on opting out.
Last October, The Herald revealed senior police officers were concerned over the prospect of losing the EAW.