Associate Minister for Immigration Kris Faafoi has been asked to intervene in the case of Mark Middleton - who faces deportation after living in New Zealand 56 years.
Mr Middleton has been accused of being in the country unlawfully after going to Fiji for a holiday in 1986 - the first time he had gone overseas since moving here with his family.
Mr Middleton is the stepfather of Karla Cardno - a teenager from Lower Hutt murdered in 1989. She was abducted by Paul Joseph Dally as she rode her bike home from the shops.
Dally raped the 13-year-old, severely beat her, then buried her alive. He was jailed for murder in 1990.
If the request for Ministerial Intervention failed, Mr Middleton feared he'd be sent to back England, the country he hadn't returned to since he left as a 4-year-old.
He had not been able to find out how he had ended up an overstayer.
"My lawyer and I have been sending emails to Immigration now all last week, over the weekend and today, asking for the file. They're not giving it to us at the moment, and I don't know why."
Mr Middleton said he had been told Immigration sent him a letter 30 years ago - but he did not remember getting it.
He was arrested while at work last week - and told Checkpoint how that unfolded.
"I got a call in the morning from the Lower Hutt Police Station asking me if I'd go in, and I said 'yip not a problem' ... I said I'll pop down and be in the police station at 4 o'clock.
"But anyway they turned up at my work and got me out on the pavement and arrested me and took me down to Wellington Central and you know took a few of my things off me, my belt and my shoes, and chucked me in a cold cell for a couple of days."
He said the police had treated him with hostility, telling him they had no records of him pre-1986, and that he had sneaked into the country.