Deputy leader Nicola Willis said the photo of the "trophy" rack made her feel "pretty yuck".
Uffindell has been suspended from National's caucus over allegations by a former flatmate that he was aggressive and intimidating to the point where she fled the property through a window.
Luxon said he was firming up the terms of reference for Maria Dew QC's investigation into those claims and expected to receive the findings in two to three weeks.
The ODT yesterday spoke to several of Uffindell's former teammates who played for the Dunedin Rugby Club alongside him in 2005.
While none of the men would agree to their names being published, they were unanimous in their defence of the politician.
One ex-player, now living overseas, described Uffindell as "a great husband and father" and said he had contacted him to give him his backing since the scandal broke this week.
"The guy is passionate about wanting to make NZ a better place," he said.
Another ex-rugby team-mate spoke in glowing terms about Uffindell.
"I knew him pretty well," he said. "He was a good dude. Just a student living the student life ... I never saw the other side that's been mentioned."
The man believed the scrutiny the MP had come under was unfair.
"It's people throwing stones into glass houses," he said.
"Unfortunately, some get crucified for what they do when they're young."
Uffindell has denied any accusations he was involved in bullying or intimidatory behaviour while at university.
In a statement, he said he enjoyed a student lifestyle, which included "drinking" and "smoking marijuana".
Luxon conceded that the saga showed the party needed to improve its candidate-selection policies.
He said he took the issues swirling around the stood-down new MP "incredibly seriously" but it was too soon to discuss the possibility of a byelection in Tauranga.
Uffindell's Dundas St home in 2004 was considered a health hazard by a council environmental health as the accumulated rubbish provided an ideal environment for maggots, flies and rats.
The MP, then a third-year arts and commerce student, admitted the tenants had not always been responsible but said the flat was substandard.
Uffindell has been under the spotlight after it was reported that he was asked to leave Auckland's Kings College for punching a younger student several times in 1999 as a 16-year-old.