Trucking lobby group Road Transport Forum gave nearly $100,000 in donations to political parties and candidates for last year's election, saying it was to help get access to MPs to discuss their issues.
The donation returns of political candidates reveal the group - which is a strong advocate for roading and trucking - gave $5000 each to nine MPs from both Labour and National.
Its chief executive Tony Friedlander said the group had also donated $30,000 to the National Party and $20,000 to the Labour Party - making its total donations $95,000.
Mr Friedlander said donations were offered to a range of candidates from different parties.
"It's getting one in each of the different parts of the country so that our members in that area can go and talk to them about issues that affect our industry. It's simply assisting the democratic process."
Fletcher Building also confirmed yesterday it had donated $20,000 to each of National, Labour and the Maori Party.
Although party returns are not due until the end of the month, the donation to the Maori Party was discovered when it was mistakenly included in co-leader Pita Sharples' candidate return.
While the company has donated to both National and Labour before, a spokesman, Phillip King, said it included the Maori Party in 2008 "because they are a credible political force. And they asked".
Those who declared donations of $5000 from the Road Transport Forum were National's Tau Henare, Eric Roy, Nick Smith, Anne Tolley, and Chris Tremain, and Labour MPs Shane Jones, Trevor Mallard, Damien O'Connor and David Parker.
Mr Parker - Labour's spokesman on climate change - said as long as the donation was transparent he saw no reason to refuse it.
Under the new disclosure rules introduced under the Electoral Finance Act, candidates have to disclose all donations of money, goods or services worth more than $1000 and cannot accept anonymous donations of more than $1000.
A mystery entity called Toorak Chambers also gave $3000 each to National MPs Simon Bridges, David Bennett, Todd McLay, and Lindsay Tisch.
When questioned, one of the recipients said it was linked to the National Party and referred the Herald to the party's headquarters.
However, phone calls to general manager Mike Oldershaw and president Judy Kirk were not returned.
The returns reveal that the fishing industry was also supporting various candidates - Peter Talley gave $10,000 to Shane Jones and Talley's also gave $5000 to Kaikoura MP Colin King (National).
Kypros Kotzikas - the president of United Fisheries - gave $5000 to Nicky Wagner and Independent Fisheries gave $3000 to Labour's Clayton Cosgrove.
Mr Jones put his $10,000 donation from Peter Talley down to their common Dalmatian ancestry.
TOP FIVE CANDIDATES' DONATIONS
1. Allan Peachey, National: $46,250. Includes $10,000 from each of Ricoh Ltd, Incentive Solutions, Corporate Cabs, and Adfit Membership Services.
2. Brendon Burns, Labour: $38,117.12. About $16,000 from a regional fundraiser, which included $2000 from children's author Joy Cowley.
3. Chris Carter, Labour: $38,000. Includes $5000 from James Zhu (principal of International College of Auckland) and $8000 from fruit and vegetable chain store owner Lim Nam Chhour.
4. Jonathan Coleman, National: $36,323.14. Includes $16,672 from Brian Choi Trust (contribution donations) and $5000 from Barfoot and Thompson real estate director Garth Barfoot.
5. Simon Bridges, National: $34,308.42. Includes $3000 from commercial real estate company CPS Partnership, $2500 from property developers Zariba Holdings, and $3000 from Realty Services. Also free timber worth $1308.42 from Bob Clarkson's company.
Prime Minister John Key: $21,500, including $15,000 from Kyounggen Lee of Epsom.