Tighthead Sinckler, 24, was returned to his upmarket hotel in a police car hours early on Sunday after police attended an incident involving "minor disorder" in central Auckland.
"A male was placed under arrest but was not charged after further inquiries established that the incident did not warrant prosecution," police said.
It is understood the incident took place on Galway St in central Auckland about 3am.
Hours earlier the 122kg Sinckler had come on in the third test at Eden Park, with the 15-15 draw earning the British and Irish Lions a share of the series.
On Tuesday, Sinckler said: "I apologise for putting myself and the Lions in this position and also to the police and anyone else affected".
"We have been informed by Auckland police about an incident involving Kyle," said Spencer, a member of the 1971 Lions team that beat the All Blacks.
"I have spoken to Kyle and reminded him of his responsibilities as a Lion, which extend to his off the field behaviour.
"Kyle has apologised for any inconvenience caused and we are satisfied that he regrets this incident and that this is the end of the matter."
Police refused to make any further comment in relation to the incident.
The incident involving the 24-year-old comes at the end of the six-week tour, with the side due to fly home today after drawing the series against most predictions.
Sinckler's arrest came a week after coming to blows with All Black reserve halfback TJ Perenara in the final tense minutes of the second test in Wellington, an altercation both Lions assistant coach Graham Rowntree and All Blacks coach Steve Hansen dismissed as a heat of the moment thing.
"Tempers got a bit out of control, maybe, that happens," Rowntree said.
Sinckler has openly addressed anger management and self-control issues in the past, having had a "fiery temperament" since he was a kid.
A mobile prop who once played in the backs, Sinckler played a role off the bench in all three tests. He started playing rugby aged eight for the Battersea Ironsiders, then was picked up by the Harlequins club.
He started the tour after being a fringe member of the England squad, and played himself on to the bench. A superb runner with the ball, he was one of the characters of the Lions team, his soft voice concealing a tough background as a London youngster.
He said he had a fiery temperament since he was a wee kid, well before he was signed-up by the Harlequins club that is based near England's famous home ground in Twickenham.
"I started playing rugby when I was eight or nine," Sinckler said. "I used to play football and I used to keep getting sent off all the time, and then my mum was just speaking to a friend on the phone one day and they said 'you should bring Kyle down to the local rugby club'."
So he switched codes, tootling down to the nearby club in his Manchester United kit. He played centre until he was about 13.
"I got scouted by Harlequins because I was playing against the backs coach's son, and I think I got sent off in that game as well," he guffawed.
Sinckler admitted he didn't have a grip on his self-control. From being a young fellow who could have hung around with the gangster types who frequented his south London housing estate, he graduated to being an England representative at various age-group levels.
In November earned his first test cap as a replacement against South Africa.
It has been well documented he wanted to make his single mum Donna proud, using that as the carrot to not stray outside society's laws.
On the rugby field he still struggled to remain inside the boundaries. The law book didn't allow 122kg props to keep pushing their luck and a couple of his team-mates at Harlequins sat him down and read the riot act.
"We played Wasps last year," Sinckler recollected on this tour. "I was fuming because we were playing so bad, and I could have got sent off two or three times in that game. James Horwill and Adam Jones sat me down on the Monday after and said 'you have to stop it - it is all about you, that is how it comes across."'
Prop Jones and lock Horwill played for Wales and Australia respectively. Rough-edged England prop Joe Marler also made it his business to tell Sinckler to wake-up to himself.
"He (Marler) is always having a go at me, telling me to shut up and stuff. It is an ongoing process for me. I want to play on the edge, to be physical and in people's faces. But in the right way and not to the detriment of the team."
Photo: GETTY IMAGES (British and Irish Lions prop Kyle Sinckler argues with Ardie Savea and TJ Perenara after the second test).