The government of Mozambique has declared three days of national mourning for people who were poisoned by bad beer at a funeral on Friday. Doctors are fighting to find a cure. (Reuters)

At least 72 people who drank a homemade beer at a funeral in Mozambique over the weekend have died, health officials said on Tuesday. Authorities believe that the beer, a traditional millet-based brew called pombe, was poisoned during the course of the funeral.

While the death toll has gone up, the number of individuals hospitalized from the beer has dropped dramatically. There are currently 35 in the hospital following the apparent poisoning, regional health official Paula Bernardo told the Associated Press. On Monday, more than 169 people were reportedly still seeking treatment.

“As we prepared to determine the cause of death of people we began to receive a lot of people with diarrhea and other muscle aches. After that we began to receive dead bodies from several neighborhoods,” Bernardo told a state-run radio station in Mozambique.

Officials believe that the brew was poisoned some time during the daylong funeral, but have few leads on the cause or motivation. Those who drank the brew only in the morning had no signs of illness, the Associated Press reported Monday. But those who drank in the afternoon were sick by the next morning.

The woman who brewed the beer was among the casualties, the AP reported.

The government has declared three days of national mourning, Radio Mozambique added.

The tragedy has attracted international attention for what health officials say is the unusual source of the poison: crocodile bile. Carle Mosse, a provincial health director, told reporters that some suspected the brew was poisoned with crocodile bile. So did a district health official, Alex Albertini.

But it’s not clear where the evidence for that suspicion is coming from. Testing has not yet been completed on samples taken from the brew and from victims, according to the BBC. The samples sent to the National Laboratory in the capital city Maputo contain “suspicious objects found inside the drum” where the beer was stored,Reuters notes.

To make things even more complicated, the AP reported on Tuesday that the drum in which the beer was held has since “disappeared.”

There’s also the question of whether crocodile bile is even poisonous at all.

“The use of bile is not uncommon in the production of local or poor quality beer but is not known to be toxic to the extent this outbreak shows,” Christian Lindmeier, a World Health Organization spokesman, said in an e-mailed statement on Monday. The WHO was trying to get more details on the mass poisoning from local partners in Mozambique.

On Tuesday, the AP added the skeptical voice of South African crocodile farmer Johan Marais to its reporting on the tragedy. Marais, the AP wrote, “has tested many parts of the animal for consuming. He said that the animal’s bile, a greenish-brown liquid produced in the liver and stored in the gall bladder, was found not to be toxic.”

Research on the subject isn’t easy to find in scientific literature. The most thorough examination of crocodile bile as a poison appears to be a 30-year-old paper by N.Z. Nyazema, who noted that bile from the gall bladders of crocodiles (also known as “nduru”) has long been rumored to be a potent toxin, often associated with poisonings at special occasions, like a funeral, or

It is reported that the poisoning occurs at special occasions like beer drinking: The nduru is said to be introduced into the beer by dipping the finger or nail where a small amount is placed: This will suffice for the purpose. The unfortunate victim is supposed to die within 24 hours. The poison is supposed to manifest itself when the patient develops pains mainly in the abdomen.

David Kroll, a science writer for Forbes, was also suspicious of the claim that crocodile bile is to blame for the deaths in Mozambique. Noting that Nyazema’s rudimentary testing of the bile’s potentially toxic effects in a small grouping of samples produced no evidence that the substance on its own lived up to the legend, Kroll writes: “I can’t imagine just how much bile would’ve had to be added to 210 liters of brew for so many deaths to occur.”

Kroll, again citing Nyazema’s work, notes that the region contains at least a dozen plants from which cardiac glycosides can be derived. In toxic doses, cardiac glycosides can “slow the heartbeat to zero” and cause symptoms like “nausea, vomiting, abdominal discomfort, and diarrhea,” consistent with what little information is available on the Mozambique deaths.

On Tuesday, the WHO’s Lindmeier emailed The Post to add that “a very common cause of mass poisoning associated with home brewed drinks is methanol, added to make the drink stronger.”

“With methanol, though, it is important to conduct a very timely testing of the blood samples, otherwise traces might be hard to detect,” Lindmeier said. As of Tuesday, the WHO had not obtained results of any testing to the samples taken of the beer or its victims.

It’s possible that the poison in question contained both crocodile bile and these plant-derived glycosides, or methanol, or something else entirely. But we’ll have to wait for the test results to be sure of anything.

[this post, originally published on Monday, has been updated multiple times.]