A letter from the Canada Revenue Agency has left a group of Waterloo Region nature-lovers scratching their heads.

The letter arrived in March, telling the Kitchener-Waterloo Field Naturalists that they were being audited – not for their financials, but for their political activity.

As a registered charity, the group is allowed to spend up to 10 per cent of its budget on political activity, although none of that activity can be partisan in nature.

“We trust that (the Kitchener-Waterloo Field Naturalists) will take appropriate action, as necessary, to remain compliant with the provisions of the act, including refraining from undertaking any partisan activities,” the letter read.

Despite the language, the letter concluded that there was no reason to revoke the group’s status as a registered charity.

Graham MacDonald, the group’s former president, says nobody is entirely sure why the letter was sent.

One possibility lies in a newsletter posted to the group’s website a few days before the letter arrived, in which MacDonald mentioned the prime minister.

“We are now hearing that Harper’s minions are at it again,” he had written.

Since the letter was sent, MacDonald says, the group has had no further contact with the CRA.

An interview request sent to the CRA on Monday was not returned before this article was published.