"I had submitted my nomination form for this election within Labour's internal timeframe but the subsequent lockdown enabled me to spend more time with my family and reflect on my political career."
But he further elaborated when speaking to the Herald, saying run-ins with Smith on the justice committee played a part in his decision to retire.
Huo was elected to Parliament in 2008 and was recently the chair of the Justice Committee.
In March, Smith took his concerns about China-expert Anne-Marie Brady being barred from presenting her views on foreign interference in elections to the media.
Huo said this was a procedural decision and Brady had not submitted her application to present to the committee in time.
But, at the time Smith said Huo was "blocking New Zealand's leading academic on the issue of foreign interference in one's democracy".
Speaking to the Herald today, Huo said Smith had leaked internal voting of the committee to the media.
"My identity as a 'Chinese-born' member of Parliament was brought into the picture."
He was highly critical of Smith's behaviour during this period.
Huo said that he gave "100 per cent" as an MP.
In response to Huo's comments, Smith said that the Labour MP had "inappropriately" blocked Brady from submitting to the Justice Committee
He said Huo was "less than honest publicly" about why he did not want her to submit.
"It was my duty to call him out on this issue of foreign inference by foreign powers."
Huo joins a growing list of MPs retiring at the election – many of which are National MPs.
In the Labour statement, he said: "For too long my family has been secondary and the recent lockdown provided an opportunity for me to reflect on my future."
"I am proud to have been Labour's first Chinese-born MP."
He said that over recent weeks, he has spoken to his friends, his team, supporters and the community about his intention to retire from Parliament.
"One of the highlights of my parliamentary career was working on the establishment of the New Zealand Chinese Language Week which has been running since 2014.