Graham Wallace was at McDonald's in Lower Hutt with his grandson Robert Knuckey when five police officers swooped on them thinking the boy was kidnapped youngster Jayden Headley.
Mr Wallace said he and Robert were separated, made to go to the police station, and questioned separately, even after
their identities were established.
They were kept by police for two hours.
Mr Wallace said it was an unpleasant experience and he was afraid for his grandson.
Robert said he gave the police his full name, details of his parents and where he was from, the Domionion Post reported..
"They were calling me Jayden, they said, 'Are you Jayden?' I asked them to stop trying to call me Jayden, and I started to cry."
Police said reports from people mistakenly thinking they had spotted the kidnapped boy and his grandfather had increased.
They said in this case a McDonald's employee had phoned them with a tip-off.
Dick Headley and his daughter Kay Skelton face kidnap charges after six-year-old Jayden, who was in the custody of his father, was snatched from outside Hamilton Public Library in August.
Jayden is believed to be somewhere in Northland with Headley.
Skelton is in prison for contempt after refusing to reveal her son's whereabouts.
- NZPA
