A Progressive Conservative constituency association received roughly $850 in corporate donations at an event last year in violation of Manitoba's election financing law, provincial elections commissioner Bill Bowles has ruled.

However, Bowles added that the infraction was unintentional and does not warrant any charges.

"Although I have found that these contributions were made in contravention of the act, I have concluded that it would not be in the public interest to commence a prosecution," Bowles wrote in a report released this week.

Bowles investigated a complaint from the Opposition New Democrats regarding a fundraising golf tournament held by the Tory constituency association in St. Vital, a Winnipeg seat held by Crown Services Minister Colleen Mayer.

The tournament included prizes such as cupholders donated by the Insurance Brokers Association of Manitoba and Brio Insurance. Staff from both groups helped out at the event during paid work hours.

Bowles ruled the staff time and prizes violated the province's ban on corporate and union donations. Only individuals can donate money, goods or services.

He said the donors could have received better guidance from the constituency association on the rules.

"Unfortunately for them, any guidance they received from the constituency association was inadequate to ensure compliance with the (law), specifically as it related to non-monetary contributions."

Bowles ordered the $850 returned, and the Tories said Wednesday they had done so.

"We acted immediately upon his report being issued and the contributions in question have been returned," party president Keith Stewart said in a written statement.

The New Democrats said the donations point to a too-cosy relationship between the Tory government and the insurance industry.

The golf tournament was held one month after Mayer was elevated from the backbenches to her cabinet portfolio, which includes Manitoba Public Insurance. It also came at a time when the Crown utility was starting negotiations on a new compensation agreement for brokers that offer its auto insurance.

'It is no accident': NDP

"Why would (the brokers association) be at her fundraiser at all?" Mark Wasyliw, an NDP candidate in the upcoming election, said on behalf of the party.

"It is no accident they're there ... because they're in the middle of high-stakes negotiations over money for their members."

The elections commissioner's office has found previous breaches of the election financing law in the past and opted not to prosecute.

In the 2011 election, two NDP cabinet ministers were deemed to have broken a rule that banned government advertising and promotion in a pre-election period when they took part in a media tour of a new birth centre in Winnipeg. Bowles ruled the infraction was inadvertent and there was no penalty.

A few years after the 1999 election, the commissioner's office found the NDP had misreported donated volunteer work from labour groups as an expense. The party was told to repay $76,000 in expense rebates they had received from Elections Manitoba.