The site of an oil pipeline spill is seen in an aerial photograph provided by Indigenous and Northern Affairs Canada, near Stoughton, Saskatchewan, Canada taken on January 23, 2017. INAC/Handout via Reuters

TORONTO (Reuters) - Tundra Energy Marketing Ltd on Wednesday confirmed its pipeline was the source of a leak of some 200,000 liters (52,830 gallons) of crude oil onto aboriginal land in Saskatchewan that was discovered by a member of the community last week.

“An excavation of the release site has confirmed Tundra Energy Marketing Ltd as the operator of the pipeline,” the company said in a statement, adding that it was working with regulators and the Ocean Man First Nation indigenous group to determine the cause.

The provincial government said on Tuesday that it will be investigating how long the spill went unnoticed and what leak-detection measures were in place at the site, some 140 km (87 miles) southeast of Regina.

It said on Wednesday that it hoped to send the affected section of pipeline for testing on Thursday, and that 174,000 liters (45,970 gallons) of oil had been recovered and 185 cubic meters (240 cubic yards) of soil had been removed from the site.

The spill was discovered just days before U.S. President Donald Trump signed executive orders that will move forward two controversial oil pipelines that have long been the target of opposition from indigenous and environmental groups, and could embolden protests against pipeline projects on both sides of the border.

The leak occurred on a feeder artery of the more than 1,600-km- (994-mile-)long southeast Saskatchewan pipeline system that Tundra, part of Canadian grain trading and energy conglomerate James Richardson and Sons Ltd, purchased from an affiliate of Enbridge Income Fund Holdings Inc late last year.

“The spill confirms the worst fears of indigenous communities and environmental organizations and no doubt strengthens their resolve to resist and fight back the approved Kinder Morgan and Line 3,” said Rauna Kuokkanen, an associate professor of political science and indigenous studies at the University of Toronto.

The federal Canadian government in November approved Kinder Morgan Inc’s hotly contested plan to build a pipeline from the Alberta oil sands to the Pacific Coast and Enbridge Inc’s replacement of Canadian segments of its aging Line 3 from Alberta to Wisconsin.