Former All Blacks captain Tana Umaga has joined Sir John Kirwan in expressing his surprise at Jerry Collins' arrest in Japan.
Umaga told international news agency AFP he had not spoken to Collins but was concerned for his former teammate.
"I'm not really too sure what's happened," Umaga said. "We're all worried about him and we just want to see how he his."
The 32-year-old Collins was arrested at the weekend after he was discovered to be carrying a 17cm knife in a department store in the city of Hamamatsu.
It is illegal to carry weapons with blades longer than 15cm without police permission in Japan.
The 74-test veteran Umaga told AFP he "felt like everyone else" when told of Collins' arrest and would continue to support him.
"He's not the best to be contacted but usually he's good at contacting people so we'll wait and see. Hopefully he's all right. That's the main thing."
Former Japan and current Blues coach Sir John Kirwan weighed in on the 32-year-old's arrest yesterday, warning the former All Black would find few favours with Japanese police.
"The Japanese are very, very strict on those types of things. You don't get a warning - you get put in jail. There is no leniency," Kirwan said.
"There have been a couple of situations where players have had little misdemeanours - what we would call a misdemeanour - and ended up in jail for two weeks."
Collins has not been formally charged yet but remains in police custody. His agent Tim Castle said he was looking into reports Collins had been carrying the knife for self defence and whether he had been involved in a bar incident before his arrest.
Collins played for Yamaha Jubilo in Japan's Top League from 2011 and left the team last month when his two-year contract expired.
He played for New Zealand in 48 tests, including one as captain, from 2001-2008.