Harry Brook, the England U19 captain, was dropped for the final game of their ICC Under 19 Cricket World Cup campaign after breaking a team rule.

An ICC media release initially confirmed that England had reported his omission was for "a disciplinary matter, but are yet to disclose the reason". Vice-captain Will Jacks was put in charge for England's seventh-place playoff against New Zealand in Queenstown.

England have privately intimated that Brook's single-match suspension arose from a relatively minor indiscretion and did not involve excessive drinking.

Speaking after England's victory over New Zealand in the seventh-place play-off, Under-19s coach Jon Lewis said: "Harry missed the match because he broke a team rule, so we decided to leave him out and deal with it internally. We'll let you know if anything happens after that.

"The team exists and the rules apply to everyone so the captain breaks the rule and he missed the game. One thing I would like to stress about this group of people is that they've been extremely well behaved here in New Zealand. They're a really good group of people. We take a lot of pride in our duty of care for the Under-19s as a support staff and we do put rules in place. If rules are broken then disciplinary action sometimes needs to be taken."

Brook, who broke into Yorkshire's 1st XI on several occasions last season, had enjoyed an excellent tournament with the bat, scoring 239 runs including two half-centuries and a century, averaging 119.5, although he made a duck in England's Super League quarter-final defeat - one of eight victims for Australia's long-haired legspinner Lloyd Pope as he shot to prominence in spectacular fashion. Defeat continued England's abysmal record in Under-19 tournaments.

The ECB had sought to impose a more disciplined atmosphere on the England Under-19 set-up in recent years, irrespective of wider concerns, partly because of a conclusion that England age-group sides matured less quickly, partly because of a legal duty of care with several players in the squad not yet 18. Players are expected to gain permission and sign-out for an evening away from the team hotel. They must stay in groups, observe an 11pm curfew, limit alcohol intake and avoid dangerous outdoor pursuits.

Nevertheless, Brook's omission on disciplinary grounds, however technical, continues a problematic winter for England. Their Ashes campaign, which ended in a 4-0 defeat against Australia was tarnished by off-the-field allegations about behaviour.

In the febrile atmosphere which originated from a police investigation into Ben Stokes' conduct outside a Bristol nightclub in September (Stokes was later charged with affray), England's behaviour in Australia has been under constant scrutiny.

Jonny Bairstow was widely ridiculed for a headbutt greeting to Australia's batsman Cameron Bancroft in a Perth nightclub at the start of the tour and, in the same bar, the England Lions batsman, Ben Duckett, was suspended from all remaining matches on the tour, fined the "maximum allowable amount" and given a final written warning about his conduct after pouring a drink over James Anderson.

Just as they restored equilibrium with a triumphant 4-1 win in the one-day series, England are again creating interest for the wrong reasons.