Chinese nationals Shang Feng Jiang, 23, Hua Li, 32, Yu Xuan Wang, 23, and Guo Hua Zheng, 42, were detained after landing at Glasgow Airport in May.
After speaking to border officials they were arrested and held in police custody.
Last month they all pleaded guilty to breaking the Identity Documents Act by knowingly being in possession of passports issued by the Republic of Korea which they knew to be false.
Sentence on all four was deferred so they could be assessed by social workers and they returned to court yesterday to be sentenced.
Paisley Sheriff Court heard the three men and the woman had gone from China to Italy before arriving in Glasgow. All four have now claimed asylum and wish to remain in the UK. The court heard they had been trafficked into the country by gangsters in China.
Solicitor advocate Robert Kerr, representing Li, said: “Her reason for her coming into the country would appear to be that she was essentially being trafficked by a loan shark in China.
“She was fearful that threats made by that individual in relation to her children would be carried out if she didn’t, essentially, allow herself to be trafficked. All of that will be scrutinised by the Home Office.
“She has applied for asylum and wishes to remain in this country.”
It is understood Li ran up a debt with the gangsters to pay for medical treatment for her children and was left unable to pay them back when her husband abandoned the family.
Mr Kerr, who was also representing Zheng, said he too wished to remain in the UK after the court case was dealt with.
Joya Madulin, representing Jiang, said he had been trafficked to wipe out a debt.
She explained: “His plea was entered on the basis he also was a victim of human trafficking on account of having owed money and being trafficked to wipe out those debts.
“He doesn’t want to go back to China. If he were to be deported back he would attempt to leave again. His mother seems to have passed away in 2012 and he has no other support there. Everyone has to live somewhere.”
Emma Crilly, representing Wang, said he knew jail was inevitable, adding: “He is fully aware his actions in coming to this country were incorrect and he advised me there was no malicious intent in these actions.”
Fiscal depute Frank Clarke told the court that protocols for dealing with fast-track asylum claims had recently changed.
He explained: “Under new procedures, asylum claims are not pursued until a court case or, indeed, sentence has been concluded. Should the four individuals be released today, the Home Office will detain them no further.”
As he jailed all four for 155 days, reduced from 180 days after they pleaded guilty, Sheriff Seith Ireland said: “The parliament of the UK has passed a law which specifically makes it an offence to have a false travel document when arriving in the UK.
“The court has to mark the serious nature of your offence.”