A group of Republican lawmakers in the United States is demanding answers from Pfizer regarding a financial contribution in Canada – alleged to be a small contribution.

They wrote a letter to the CEO of the pharmaceutical giant questioning him about the donation to Dying With Dignity Canada, a group that advocates for medically assisted death.

Senator Marco Rubio and his colleagues, in their letter, pointed out that Pfizer is listed among thousands of donors in the group’s 2022 financial statements. The document does not specify any dollar amounts.

When CBC News contacted the group, a spokesperson for Dying With Dignity Canada said Pfizer’s contribution was just $50, or about $37 US.

She said this was part of the company’s matching gift program for employees, as the company matched the employee’s $50 contribution.

Sarah Dobek, a spokesperson for Dying With Dignity Canada, said: "That’s why Pfizer was listed among our donors for 2022."

Dying With Dignity Canada does not have a corporate fundraising program, nor do we have relationships with pharmaceutical companies. Nearly all our donations come generously from individual donors who support end-of-life rights and choice.

In their letter sent Wednesday to Pfizer CEO Albert Bourla, U.S. senators expressed concern about the contribution.

The letter sent by Rubio and a group of conservative colleagues, including Ted Cruz, JD Vance, John Hawley and others, states: "We write in response to concerning information."

They said Canada has among the most liberal policies in the world regarding medically assisted death, but said Canada is pushing for "more extreme" policies.

They pointed out that the organization supports expanding the right to medically assisted death to include some minors.

The lawmakers posed a series of questions, including "Does Pfizer support these policies?" and "Are Pfizer products used to assist in death?"

The letter comes after Canada’s assisted death policies have drawn considerable media interest in the United States. Many conservatives in the United States have also criticized Covid vaccines, which Pfizer helped bring to market.

When CBC News contacted the company, Pfizer only said it is "not a direct donor company" to Dying With Dignity Canada."