BANGKOK — A Thai activist accused of insulting the country's monarchy has died in detention following a months-long hunger strike.

Netiporn "Bung" Sanesangkhom died after her heart "stopped suddenly" on Tuesday morning, officials said.

The 28-year-old, part of a small pro-democracy group, had been detained since 26 January, facing seven separate charges — including two of insulting the monarchy.

She began her hunger strike the next day, only accepting water once again in late February, and food from April.

Ms Sanesangkhom was demanding reform of Thailand's justice system.

She had initially been held on a contempt of court charge, with her detention extended after bail in a separate lese-majeste case was revoked, Reuters news agency reported.

Ms Sanesangkhom was accused in two cases of lese-majeste case — which forbids insulting the monarchy — including one relating to a poll she took part in on a royal motorcade during pro-democracy protests in 2020.

If found guilty, Ms Sanesangkhom — a judge's daughter who previously worked as a tutor — was facing up to 15 years in prison for each charge.

Thailand has some of the strictest lese-majeste laws in the world. According to legal aid group Thai Lawyers for Human Rights, around 260 charges have been filed under the lese-majeste law since 2020.

This was not the first time Ms Sanesangkhom had gone on hunger strike. Back in 2022 she and a fellow activist from Thaluwang — which translates as "shattering the palace" — were released from prison after refusing to eat for 64 days.

It is not clear exactly how long she refused food on this occasion. Thai Lawyers for Human Rights said she started accepting food again in April.

She had been sent to a prison hospital due to declining health.

According to prison officials, the hunger strike had left her weak and suffering from anaemia, but a statement from the Department of Corrections said she refused vitamins and electrolytes offered.

Her heart stopped early on Tuesday morning, the statement said, with doctors attempting to revive her for several hours before she was sent to a nearby hospital where she was declared dead.

Thai MP Rukchanok Srinork — who is on bail while appealing against a six-year sentence for convictions including lese-majeste — pointed out several other detained activists were also on hunger strike "demanding their rights".

"How many times will the courts allow deaths like these to happen until they're satisfied?" she asked on X (formerly Twitter), after paying tribute to Ms Sanesangkhom. — BBC