POLICE are crying foul after claiming a growing number of legal defence teams were "ambushing" them with late evidence in sneaky bids to get their clients off.

Lancashire Police Chief Constable Paul Stephenson has lobbied the government over the problem in a bid to influence moves to change the law on disclosure during criminal trials.

But the Law Society today said that the Chief Constable's claim was unhelpful as many criminal justice agencies struggled to understand the laws around disclosure.

The police and Crown Prosecution Service have to reveal their evidence prior to the trial, but defence teams can withhold their 'hand'.

There is a growing feeling in Lancashire Police that in big and complex cases, defence barristers do not play fair in a bid to catch the prosecution on the hop and maximise their client's chances of being acquitted.

Mr Stephenson said the practice meant that police officers could be suddenly taken off the streets in a bid to frantically disprove the claims against the clock.

He added: "Defence teams should have to disclose items to us instead of us being ambushed."

Mr Stephenson met top-level officials from the police standards unit and the government in Westminster this month and raised his concerns about the problem.

He told them about the trial of Andrew Shacklady as a typical example of what they were finding.

Drugs baron Shacklady, 34, from Leyland, was jailed for life earlier this month after a jury found him guilty of murdering former a henchman -- despite a number of late disclosures by his defence team.

A police source said: "As the trial was progressing - and bear in mind it had been going on for some time -the defence team were producing witnesses who were coming to court and giving versions of events to try to disprove certain points made by the prosecution.

"So we were working at the 11th hour and 59 minutes. There was a lot of rushing around to disprove what they were saying.

"It is an issue of frustration in long, complex cases when we feel we are going the extra mile but it seems the defence don't have to comply."

A Law Society spokesperson said: "It has been recognised by government research that all criminal justice agencies including the CPS, police and defence teams struggle at times to comply with the legislation.

"It is unhelpful and inaccurate to blame just one agency. The Attorney General is currently reviewing the guidelines on disclosure and the Law Society is involved in this consultation as are the other agencies."