(Adds pension fund comment)
COPENHAGEN, Dec 21 (Reuters) - The Danish Tax Agency said on Friday it had subpoenaed a foreign pension fund, later identified as Canada's Health Care of Ontario Pension Plan (HOOPP), saying the fund had received dividend tax rebates it was not entitled to.
The tax agency said the rebates had totalled 900 million Danish crowns ($138 million) from 2011 to 2014, although it said the fund - which it did not name - had not made any fraudulent transactions.
HOOPP later confirmed it was the fund. "We intend to resolve this issue in the best interests of our organization and our members," it said in an emailed statement.
The fund, whose members are healthcare workers in the country's most populous province of Ontario, said it has invested in Danish capital markets for a number of years, buying shares of listed companies through Danish brokerages.
It argued that under a tax treaty between Canada and Denmark it was entitled to the refunds, and that Danish pension funds are treated similarly in Canada.
The tax agency said it had been in a dialogue with the pension fund but had not been able to reach an agreement and that it therefore subpoenaed the fund to get the money. The agency disagreed with HOOPP over whether the fund was actually the owner of the shares at the time it had sought refunds.
HOOPP had claimed a further 1.3 billion crowns in dividend tax refunds after 2014, but this money was never paid out, it said.
It added that HOOPP was not part of a massive stock trading scam that it is investigating as it tries to recover $2 billion of tax rebates it was tricked into paying.
Danish authorities have subpoenaed more than 420 companies and people they suspect of involvement in that scheme, freezing hundreds of millions of euros of assets around the globe.
"The Tax Agency does not consider it to be a fraud case because, contrary to the fraud cases, this is an actual pension fund with around 300,000 members," it said. (Reporting by Teis Jensen and Emil Gjerding Nielson, additional reporting by Allison Martell in Toronto; Editing by Angus MacSwan and David Stamp)