Saskatchewan Premier Brad Wall says the more than $3 million paid to an American law firm to lobby for projects such as the Keystone XL oilsands pipeline is money well spent.

The Toronto Star reports public documents show that since 2009, the Saskatchewan government has paid Nelson Mullins Riley and Scarborough to help Wall lobby in Washington.

The paper also says the documents show some U.S. congressmen received political contributions from the law firm before or after meeting with Wall.

Wall says the money is being spent to promote Saskatchewan interests in the U.S., something he says wasn't being done under previous governments.

He says the firm has many Canadian clients pursuing similar interests and he is confident none of the payments to congressmen were on behalf of the Saskatchewan government.

The opposition NDP says the millions of taxpayer money paid to the law firm seems to have done very little for Saskatchewan.