The home secretary is asked why North Wales Police were told to release a group of illegal immigrants and let them get to an asylum screening centre.
Police contacted the Home Office to alert them of the arrests
It is understood that earlier this year officers arrested five men - believed to be from Iraq and Iran.
The police contacted the Immigration and Nationality Directorate and were told to let them find their way to a asylum screening centre in Liverpool.
Chief Constable Richard Brunstrom has written to John Reid about the matter.
The Home Office said there were "rare occasions" when staff might not be able to attend after police made arrests, such as targeting illegal working or removing failed asylum seekers.
Shadow Welsh Secretary Cheryl Gillan, who has raised the issue in the Commons, said Home Office officials had even provided a "helpful map" for police to pass on to the men, who had been found in the back of a van which had been stopped.
The map gave directions to an asylum screening centre in Liverpool.
It has emerged that one of the arrested men was carrying a document which confirmed that days earlier he had been refused permission to enter the UK.
The Home Office would not comment on individual cases but sources told the BBC that the five men at the centre of the debate did later turn up at the asylum screening unit in Liverpool.
Ms Gillan, the MP for Chesham and Amersham, told BBC Radio Wales on Thursday the matter showed the Home Office was "a security system in chaos".
She said: "This fails both the compassion test and the security test.
"If these were genuine asylum seekers that didn't expect to disappear into the United Kingdom the moment they got inside our borders, then they will maybe have been distressed or had no money and would need help to get to the immigration offices in Liverpool.
"If not, and if the concerns of the police, and they were concerned enough about these individuals as I understand it, then the security element is not met.
Chief Constable Richard Brunstrom is awaiting a Home Office reply
"So it's demoralising for the police. It sends the wrong messages out to people that want to come into this country and it also points out a gap in the Home Office."
Immigration Advisory Service Chief Executive Keith Best said the number of people seeking asylum had fallen from 84,000 in 2002 to around 25,000.
He said arriving in the UK on forged documents was not an offence if it was the only way of escaping a tyranny.
He said: "If you were to detain every single person claiming asylum as though they were a criminal, when in fact they're not - most people want to comply with the procedures because they want to have their claim for asylum heard.
"But if you were to lock all those people up, can you imagine the impact on the prison estate of another 25,000 people going in there?"
North Wales Police said Chief Constable Richard Brunstrom had written to Home Secretary John Reid about the issue and was awaiting a reply.
The Home Office said in a statement: "The Immigration and Nationality Directorate (IND) and police already work closely and effectively and the minister for immigration has announced how he wishes to increase this level of joint working between police and the IND, especially to tackle the hard end of immigration crime.
"The Home Secretary has also made it clear that he is determined to ensure that the police and the Home Office worked in a joined up and effective manner."