More than 1,300 people died making the Islamic pilgrimage of hajj in Saudi Arabia this month, the vast majority of whom the Saudi government said did not have permits. Many walked for miles in scorching heat after paying thousands of dollars to illicit or fraudulent tour operators.

While pilgrims with permits are transported around the holy city of Mecca in air-conditioned buses and rest in air-conditioned tents, unregistered ones are often exposed to the elements. In recent days, as temperatures surpassed 120 degrees, some pilgrims described watching people faint and passing bodies in the street.

On Sunday, in an interview on state television, the Saudi health minister, Fahd al-Jalajel, said that 83 percent of the 1,301 reported deaths involved pilgrims who lacked permits.

“The rise in temperatures during the hajj season represented a big challenge this year,” he said. “Unfortunately — and this is painful for all of us — those who didn’t have hajj permits walked long distances under the sun.”

With nearly two million participating each year, it is not unusual for pilgrims to die from heat stress, illness or chronic disease. It is unclear if the number of deaths this year was higher than usual, because Saudi Arabia does not regularly report those statistics. Last year, 774 pilgrims died from Indonesia alone, and in 1985, more than 1,700 people died around the holy sites, most of them from heat stress, a study at the time found.

But because so many of those who died had no permits, this year’s toll exposed an underbelly of tour operators and smugglers around the world who profit off Muslims desperate to make the journey.

The deaths also laid bare what appeared to be a wide-scale failure of Saudi immigration and security procedures aimed at preventing unregistered pilgrims from reaching the holy sites, including a security cordon around Mecca that locks down weeks before hajj.

Saudi officials did not respond to requests for comment.

In interviews with The New York Times, however, hajj tour operators, pilgrims and relatives of the dead described easily exploited loopholes that allow people to travel to the kingdom with a tourist or visitor visa ahead of hajj, usually assisted by tour operators in their home countries. Once they arrive, they find a network of illegal brokers and smugglers who offer their services and sometimes abandon them to fend for themselves, they said.

The number of unregistered pilgrims appears to have been driven up this year by rising economic desperation in countries like Egypt and Jordan. An official hajj package can cost more than $5,000 or $10,000, depending on a pilgrim’s country of origin — beyond the means of many hoping to make the trip.

Marwa, a 32-year-old Egyptian woman whose parents performed hajj without an official permit this year, said that they had paid around $2,000 for their journey, facilitated by an agent in Egypt and a broker in Saudi Arabia. They felt that they had to go soon because, as Egypt’s currency loses value, their savings shrink every year, she said. Marwa asked to be identified only by her first name to avoid legal repercussions.

Several countries with large numbers of deceased pilgrims have moved quickly to contain the fallout.

On Friday, the president of Tunisia, which counted more than 50 pilgrims among the dead, fired the country’s religious affairs minister. In Jordan, which recorded the deaths of at least 99 pilgrims, the public prosecutor opened an investigation into illegal hajj routes. And in Egypt, the authorities said that they would revoke the licenses of 16 companies that issued visas to pilgrims without providing adequate services.

“There’s so much greed around this business,” said Iman Ahmed, a co-owner of El-Iman Tours in Cairo.

Ms. Ahmed said that she refused to send unregistered pilgrims on hajj packages but that other Egyptian tour operators and Saudi brokers made big money doing so.

One unregistered pilgrim who died was Safaa al-Tawab, a grandmother from the Egyptian city of Luxor, according to her brother, Ahmed al-Tawab. Ms. al-Tawab, 55, had not been able to obtain a hajj permit but found an Egyptian tour company to take her for around $3,000, he said.

Before the hajj, the Saudi authorities posted billboards and sent a barrage of text messages reminding people that it is illegal to perform the pilgrimage without a permit; violators face fines, deportation and bans on re-entering the kingdom.

Entry to Mecca was barred weeks before hajj for visitors without permits. Yet many pilgrims were able to evade the restrictions, arriving in Mecca early and hiding out, or paying smugglers to ferry them into the city.

One Jordanian pilgrim, who asked to be identified only as Um Abdulrahman, a nickname, because she feared repercussions, said that she encountered several smugglers to help her move around Mecca, including one who charged around $200 to drive her into the city over a rocky mountain route. But she ended up walking for hours in the sun without access to water or bathrooms, she said.

At one point, the police briefly detained her group, wrote down their names and left them in the middle of nowhere, she said. Um Abdulrahman, 49, said she knew her journey was illegal, but that she had not fully grasped the risks.

The Saudi government deploys measures to reduce the effects of extreme heat, including spraying pilgrims with mists of water. One recent study estimated that the incidence of heat stroke at hajj had actually declined — although the researchers warned that could shift as worsening heat caused by climate change outpaces measures to mitigate it.

Abdulhalim Dahir, 31, a Kenyan pilgrim who made the hajj with his brother and father using official permits, said that his journey was smooth, with air-conditioned tents, air-conditioned buses and easy access to water.

“It was an amazing experience — once in a lifetime,” he said.

But even some who were in Mecca legally complained about inadequate facilities for the heat.