A groom was arrested by immigration officials “moments before” his wedding ceremony in Liverpool was due to start.
UK Border Agency officers stopped the ceremony earlier after receiving information the relationship “may not be genuine”, a spokeswoman said.
The groom, a 29-year-old Algerian man, was arrested on suspicion of remaining in the UK illegally following the expiration of his visa.
He had been due to marry a 25-year-old Polish woman at St George’s Hall.
The bride was questioned by officers and released, while the groom was “detained pending his removal from the UK”, the spokeswoman said.
She said the ceremony was a “suspected sham marriage” and the operation to stop it had been carried out with the “full co-operation of the Superintendent Registrar”.