It is hoped up to 500 people will attend the Charity Night & Auction.
All Black great Michael Jones is the guest speaker and Police Ten 7's Rob Lemoto is the MC.
There will be live and silent auctions of items including sporting memorabilia, with a big ticket item expected to be a signed All Blacks jersey.
Senior Constable Gared McLaughlin said there were already some great items up for grabs in the auction.
Other items include pamper packages from QE, hospitality and restaurant vouchers, accommodation packages, two cycling jerseys including Julian Dean's 2007 New Zealand Championships jersey, Great Britain rider Adam Yates' Tour De France jersey, adventure tourism packages, Kylie Day Photography package and large-scale photographs of Rotorua by Graeme Murray and Adrian Hodge.
Mr McLaughlin said free courtesy vans would operate and were included in the ticket price.
Mr Wilkinson said 80 per cent of the money raised would go towards Mr Allpress' family with the remaining money going to the fund.
Mr Allpress is off work indefinitely while he fights two brain tumours, one which is considered inoperable. His partner, Kylie Parker, is on leave from her job as an ambulance officer to care for him and together they have four children.
Mr Wilkinson said Mr Allpress' illness had hit staff hard.
"He's the sort of person you'd want to do this for.
"He has good days and bad days. Hopefully he will be able to come along on the night, but he gets pretty tired. He's also pretty humble about the whole thing.
"He is still remaining positive despite it being stage 4 (terminal). He just says he doesn't listen to the doctors because it doesn't change anything for him. He's just looking forward to getting well."
Tickets can be bought from www.nduro.co.nz or by using the "book now" link on the Rotorua Police Welfare Fund Facebook page.
Anyone wanting to donate items for the auction or money to the cause can send a private message to the Facebook page.
Charity Night & Auction
Friday October 21
Tickets on sale now $75 each or $700 table of 10
Guest speaker Michel Jones
MC Police Ten 7's Rob Lemoto
Rolling food platters and cash bar
Live music