The Metropolitan Police had said they pulled a woman from the water after MP Stephen Gilbert claimed he rescued her:
"At 1950 the marine policing unit responded to reports of a woman in the River Thames near Westminster Bridge. They recovered her from the water and took her to hospital. Next of kin have been informed," the force said in a statement.
More top news
He told People Magazine: "I was in denial, but a part of me always knew this was coming."
A compound within the Conus regius snail's venom has been found to create long-lasting pain relief.
NASA says the phenomenon is "quite unusual to see".