Practitioners fear that suspects in police detention are being denied proper access to justice following reports that a call centre system for defence solicitors has gone into 'meltdown'.

On Tuesday, the Legal Aid Agency said the Defence Solicitor Contact Centre (DSCC) online portal would be unavailable from the following day for up to 48 hours for 'essential maintenance'. A phone number and email address were provided 'if you need help with anything'.

Under the Police and Criminal Evidence Act 1984, detainees are entitled to free and independent advice at any time while in police detention. However, solicitor Kerry Hudson, vice president of the London Criminal Courts Solicitors' Association, said police are struggling to log cases with the DSCC.

She said: 'When they are getting through, we are hearing of delays of four or five hours between the police first call and the DSCC then contacting the solicitor. When they are contacting the solicitor, much of the key information is missing (including the detainee name in some cases) and the crucial DSCC reference number. Solicitors cannot get paid without obtaining this reference number within 48 hours of the event so some are refusing to attend through fear of not being remunerated. Cases are also being deployed to the wrong solicitors outside of the scheduled duty slots owing to the time delays.'

Hudson warned that the system problems could affect cases that later go to court. For instance, an interview where the suspect was denied a solicitor at the police station could be excluded as inadmissible.

She said: 'It is a real access to justice problem. Who knows how many detainees across the country have gone into interview alone having been told the police cannot get through to request a solicitor to attend. This could include youths and vulnerable adults.'

Law Society vice president David Greene said denying suspects the right to legal advice risks miscarriages of justice. 'We have asked the Legal Aid Agency to provide urgent assurance to solicitors that they will be paid for work done in good faith that could not be processed in the usual way, and to explain what they are doing to resolve the problems. They have promised they are working on this,' he said.

The Society, LCCSA and Criminal Law Solicitors' Association advise members to make a detailed note of all duty attendances to claim payment, provide a direct contact number to police stations whose rotas they are on and email to request a reference number and keep clear records of any problems arising.

Practitioners are also advised to keep a detailed note of all attempts to contact the DSCC, and try to keep a copy of the custody record where it shows their firm being instructed or the client requesting a duty solicitor.

9.40pm update: A Legal Aid Agency spokesperson said: 'Planned changes to the duty solicitor website coupled with more calls than anticipated during the bank holiday weekend have caused some delays. Despite this, representation was deployed to all clients where requested. We continue to work with our provider to ensure call times are improved and that quality is maintained.'

The Gazette was told that the maintenance changes are expected to be resolved within 48 hours of the work commencing. Phone and email services remained available. The MoJ is in the process of handing over from the existing supplier, Capita, to a new supplier, HGS UK, and the IT application was being transferred over. While this was ongoing, a manual process was in place to handle calls and deploy solicitors. An increase in the volume of calls during the bank holiday and this week's IT update meant phone calls were answered slower.