Mexican NGOs on Tuesday reported an oil spill in an area of the Gulf of Mexico where an explosion this month killed two workers at a gas production platform of state company Pemex.
Satellite images show that the spill began on July 4, three days before the blast, and by last week had spread over some 400 square kilometers (154 square miles).
This was "more than twice the surface area of the city of Guadalajara," the NGOs said in a statement.
"The complete opacity with which this spill has been handled is worrying," said the NGOs, which included including Greenpeace.
Pemex, in a statement, acknowledged there was a leak but said "the volume of hydrocarbons that escaped was minimal."
It said the spill was reported to the government and Navy for repairs.
"Most of the spilled volume was recovered immediately," said the company, rejecting the scale of the spill as claimed by the NGOs.
Debt-laden Pemex has suffered a string of accidents in recent years.
In February, a dozen workers suffered burns in two fires that occurred at facilities in the southeastern state of Veracruz.
In August 2021, a fire on a platform during maintenance work left several people dead.
The previous month, a spectacular blaze and gas leak from an underwater pipeline in the Gulf of Mexico caused what was dubbed an "eye of fire" in the sea, though there were no victims.
Other incidents included fires in 2015 and 2016 on offshore installations that each left several people dead.