Europol helps support the fight against terrorism among member states
Attempts to tackle serious organised crime across Europe are being hampered because police intelligence is not shared properly, a report has said.
The Lords EU Committee said information was not being routinely passed to European police agency Europol by national police forces.
A lack of trust and fear of leaks meant information was often shared using informal links instead, they said.
And IT problems meant the UK was unable to put data on a European computer.
The report - Europol: Co-ordinating the Fight Against Serious and Organised Crime - said the situation should be addressed as a "matter of urgency".
"This will be vital in ensuring that information on organised crime in the UK and across Europe is shared effectively between police forces," it stated.
Committee chairman Lord Jopling told BBC News a failure to share information meant good police work was being undone.
He said: "Only five countries currently automatically load data on to the European information system and in the UK, for instance, they cannot currently take part in it because the British IT data systems are not compatible with Europol's.
"There is a good deal of lack of trust between the national police forces and Europol because a number of national police forces are not happy that information they may give on a confidential basis will not leak out."
Europol was founded in 1992 to improve co-operation between the police forces of EU members on issues including terrorism, drug trafficking and serious fraud.
It is based in The Hague in the Netherlands and staffed by several officers from each of the EU member states.
But the peers' committee found that rather than exchanging details of crimes centrally, officers in The Hague tended to do it more informally face-to-face.
The peers want the agency's remit to be widened to include crimes including serial murder and rape.
The report also criticised the the UK's Serious Organised Crime Agency (Soca), which has been operating since 2006, for weak links with police forces around the country.