When Jarred Shaw, an American basketball player in Indonesia, stepped down to the lobby in his apartment complex earlier this year to collect a package containing illegally imported cannabis gummies, he thought that the medicine to ease his Crohn’s disease had arrived.

It had – but so too had 10 undercover police officers. A video on social media shows Shaw, wearing a black T-shirt and shorts, shouting for help as the swarm of officers move to apprehend him.

The 35-year-old from Dallas, Texas, is facing the possibility of the death penalty or a long spell behind bars. He was a key member of Prawira Bandung, who won the Indonesian Basketball League (IBL) in 2023, and he has scored more than 1,000 points over three seasons in the country. But now he is languishing in pre-trial detention and is banned for life from the IBL for life.

“I use cannabis as a medicine,” he told the Guardian over the phone from a prison just outside Indonesia’s capital, Jakarta, in his first comments to the press since his May arrest. “I have an inflammatory condition called Crohn’s disease that’s incurable. There’s no medicine apart from cannabis that stops my stomach from aching.”

During the off-season Shaw lives in Thailand, where cannabis is subject to more liberal laws. He says he had endured the pain of going without cannabis in previous campaigns in Indonesia but says that health reasons spurred him to import the intercepted supply of 132 gummies this year. “I made a stupid mistake,” he says.

But that mistake should not warrant the death penalty or a long spell in prison, he says. “There’s people telling me I’m about to spend the rest of my life in prison over some edibles,” he says. “I’ve never been through anything like this.” In the first two months after his arrest, he was at “the lowest point in [my] life” and in a “really dark mental place”.

“I felt helpless and alone,” he says. “I didn’t want to wake up again.” But through prayer and his faith, as well as access to a prison gym, he is starting to feel himself again, even while the 6ft 11in athlete shares a cramped cell with a dozen men. “I just turned 35 but I still feel young,” says the former Utah State basketballer, who has played in Argentina, Japan, Turkey, Thailand and Tunisia. “I would love to continue my basketball career.”

Shaw, who plays as a center or power forward, says cannabis helps ease his anxiety and depression, as well as insomnia and the pain from Crohn’s. “I don’t use it to have fun and go party,” he says. “With my stomach condition, sometimes it’s hard for me to keep food down or go to the toilet. It just soothes the pain a little bit.”

Indonesia takes a hard line on drugs and carried out executions in 2016, by firing squad, of an Indonesian and three foreigners convicted of drug offenses. More than 500 people – including almost 100 foreigners – are on death row in the country, mostly for drug-related crimes.

Indonesian police have said that Shaw sent text messages to his teammates saying that he would share some of the cannabis candies with them. “What they consider drugs, I consider medicine,” says Shaw. “It’s just different cultures.”

After Shaw’s arrest, Ronald Sipayung, the Soekarno-Hatta Airport police chief, told reporters that the American could face life in prison or even the death penalty if found guilty. “We are still running the investigation to uncover the international drugs network behind this case and to stop its distribution,” Sipayung said.

Shaw was swiftly paraded at a press conference, appearing with his hands cuffed wearing an orange prison-issue T-shirt and a black face mask. He stood with his back to the audience as police chiefs exhibited the cannabis gummies, which weigh 869 grams in total and are worth $400.

He said that to charge him with possession of almost a kilo of cannabis is unjust and “sick”, given that most of the weight is made up by the gummies themselves rather than the cannabis content. “I’ve been charged for almost a kilo,” he says. “I didn’t have anything near that.”

Shaw is fundraising to cover his rising legal fees. He has not yet appeared in court despite being arrested five months ago, and he is still waiting for a first appearance date. “They’re making it seem like I’m this big drug dealer,” he says. “Why would I bring the candy here to sell? It was for personal use.”

Stephanie Shepard, director of advocacy at Last Prisoner Project (LPP), which campaigns for the release of people imprisoned for cannabis-related offences, said: “Jarred’s case is not an isolated incident. Around the world, people are serving extreme sentences for non-violent cannabis offenses that pose no threat to public safety.” Even in the US, she added, tens of thousands remain incarcerated for cannabis offences despite recreational legalization in almost half of states and a medical greenlight in all but two. “These punishments run counter to international human rights standards,” Shepard said.

The potential efficacy of cannabis on Crohn’s disease is understudied but in September the journal Nature Medicine published a paper on a study which found that cannabis can ease chronic lower back pain without serious side effects. It came as Donald Trump talked up the benefits of cannabis-based medicines.

There are parallels between Shaw’s case and that of Brittney Griner, the decorated American basketball player who was imprisoned in Russia for 10 months in 2022 after authorities found cannabis vape cartridges in her luggage. Griner was eventually released as part of a prisoner swap involving a Russian weapons trafficker.

“Jarred has always been one of the most generous and selfless people you could meet,” his friend, Bree Petruzio, said on Shaw’s fundraising page. “Jarred made a mistake. But I don’t believe that mistake should cost him his entire future.”

The US embassy in Jakarta says it is aware of Shaw’s case but would not comment further.

Donte West, an advocacy assistant at LPP who is handling Shaw’s case, said: “Cannabis can’t kill you, but possessing it can. We must get as much attention on this case in the hope that a positive resolution will set a powerful precedent. I’m dedicated to making sure Jarred gets home to his mother.”

• The Indonesian National Police did not respond to a request for comment for this story.