Peteru has been released from the final season of his contract and is the 10th player, from the 36 with a squad number at the start of 2019, to leave the club this year.
The former Gold Coast Titans man, who was on Leeds’ non-federation-trained quota, joined Rhinos ahead of the 2018 campaign and made 32 appearances, scoring one try.
A club statement confirmed the New Zealand-born prop has been “released from the remainder of his contract to enable him to pursue other opportunities”.
Peteru told The Yorkshire Evening Post: “I am happy, I am content with my decision and very grateful the club has given me an opportunity to leave on my terms.
“I think it is good for me at this stage of my career to explore other opportunities.”
Though two biceps injuries disrupted his first season at Leeds, he played in 16 of their opening 18 games this year before suffering a fractured cheekbone in May.
He returned to feature three times at the end of the campaign and made his final appearance for the Rhinos in their last game of the season, against Warrington - the club he faced on his debut.
Peteru is confident of finding a new club in this country, but added: “There’s nothing concrete yet.
“I am just exploring all my options now and looking at all opportunities.
“I am fully fit, I am 27 and I am coming into my prime now.
“That’s part of the reason for looking at other opportunities, it is in the best interests of me and the club.”
Reflecting on his two seasons at Rhinos, he added: “I have had a great time.
“I have made some great friends and met some great people. It has been a great journey for myself, playing for a prestigious club like Leeds Rhinos.
“I have really enjoyed the ride and I wish them all the best for the future.”
Peteru insisted: “I definitely think the club has a bright future. There’s a lot of young players coming through the ranks, guys like Ash Handley, Mikolaj Oledzki and Jack Walker.
“They are destined for good things and, hopefully, the club heads that way eventually. I have nothing but good words for the club; I have left on good terms.”
Rhinos’ director of rugby Kevin Sinfield said: “On behalf of everyone at the club, I would like to thank Nathaniel for all he has given to the Rhinos during his two seasons at Emerald Headingley.
“He has been a popular member of our squad and leaves with our best wishes and thanks.
“I know he is excited about the new challenges ahead and we wish him the best of luck for the future.”
Peteru’s release continues an overhaul of Rhinos’ playing group which began when Sinfield was appointed in July, 2018 and – with Toronto Wolfpack seemingly keen to sign Brad Singleton and several clubs chasing fellow front-rower Wellington Albert – other departures are possible.
Rhinos have announced only two additions for 2020, scrum-half Luke Gale and back-rower Alex Mellor, but are in the market for more signings, particularly in the pack.