Mexican congressman Sergio Gutierrez said he hoped the hearing on UFOs was the first of other similar events in Mexico.

In the hearing on Tuesday, Mexican politicians were shown two artefacts that a Mexican journalist and longtime UFO enthusiast, Jaime Maussan, claimed were the remains of extra-terrestrials.

The two tiny “bodies”, displayed in cases, had three fingers on each hand and elongated heads.

Maussan said they were recovered in Peru near the ancient Nazca Lines in 2017. He said that they were about 1,000 years old, according to carbon dating analysis by Mexico’s National Autonomous University (UNAM).

The remains were not related to any life on Earth, Maussan said.

“I think there is a clear demonstration that we are dealing with non-human specimens that are not related to any other species in our world and that all possibilities are open for any scientific institution … to investigate it,” Maussan said.

Similar finds in the past have turned out to be the remains of mummified children.

UNAM on Thursday republished a statement first issued in 2017, saying the work by its National Laboratory of Mass Spectrometry with Accelerators (LEMA) was only intended to determine the age of the samples.

“In no case do we make conclusions about the origin of said samples,” the statement said.

The apparently desiccated bodies date back to 2017 and were found deep underground in the sandy Peruvian coastal desert of Nazca. The area is known for gigantic enigmatic figures scraped into the earth and seen only from a birds-eye-view. Most attribute the Nazca Lines to ancient Indigenous communities, but the formations have captured the imaginations of many.

In 2017, Maussan made similar claims about non-human remains in Peru, and a report by the country’s prosecutor’s office found that the bodies were actually “recently manufactured dolls, which have been covered with a mixture of paper and synthetic glue to simulate the presence of skin”.

The report added that the figures were almost certainly human-made and that “they are not the remains of ancestral aliens that they have tried to present”.

The bodies were not publicly unveiled in Peru at the time, so it is unclear if they were the same as those presented to Mexico’s Congress on Tuesday.

The session, unprecedented in the Mexican Congress, comes two months after a similar one before the US Congress in which a former US Air Force intelligence officer claimed his country has probably been aware of “non-human” activity since the 1930s.

The Mexican congressman Sergio Gutierrez, from President Andres Manuel Lopez Obrador’s ruling Morena party, said he hoped the hearing would be the first of other similar events in Mexico.

“We are left with reflections, with concerns and with the path to continue talking about this,” Gutierrez said.

But Maussan faced swift backlash and criticism from sceptics on Wednesday who questioned the authenticity of his presentation.

Julieta Fierro, researcher at the Institute of Astronomy at the National Autonomous University of Mexico, was among those to express scepticism, saying that many details about the figures “made no sense”.

Fierro added that the researchers’ claims that her university endorsed their supposed discovery were false, and noted that scientists would need more advanced technology than the X-rays they claimed to use to determine if the allegedly calcified bodies were “non-human”.

“Maussan has done many things. He says he has talked to the Virgin of Guadalupe,” she said.

“He told me extraterrestrials do not talk to me like they talk to him because I don’t believe in them.”

The scientist added that it seemed strange that they extracted what would surely be a “treasure of the nation” from Peru without inviting the Peruvian ambassador.