A leading Vietnamese climate activist has been jailed for tax evasion, the latest environmentalist put behind bars by the country’s communist government.

A court in Ho Chi Minh City sentenced Hoang Thi Minh Hong to three years in prison for dodging $275,000 in taxes related to her environmental campaign group Change, her lawyer, Nguyen Van Tu, said.

The 50-year-old is at least the fifth environmental campaigner to be jailed on tax evasion charges in the last two years as Vietnam’s authoritarian government steps up a crackdown on activists.

Her husband, Hoang Vinh Nam, said he was “disappointed” at the verdict.

“The sentence given to Hong today was too heavy,” he said. “I think it was unfair to Hong. The defence lawyer did his best but his arguments were not considered properly.”

State media said the charges related to revenue generated by Change from 2012 to 2022. Hong admitted the charges and along with her family paid the state 3.5bn dong ($145,000) in return for leniency, state media said.

Hong founded Change to mobilise Vietnamese, particularly young people, to take action on environmental issues including climate change, the illegal wildlife trade and pollution. But she abruptly shut down the group last year after four environmental and human rights activists were jailed for tax evasion.

“This conviction is a total fraud, nobody should be fooled by it,” said Ben Swanton, the co-director of The 88 Project, which advocates for human rights in Vietnam. “This is yet another example of the law being weaponised to persecute climate activists who are fighting to save the planet.”

Earlier this month Hanoi police detained the director of the Vietnam Initiative for Energy Transition, an independent energy policy thinktank.

Ngo Thi To Nhien, who has worked with the EU, World Bank and UN, was reportedly working on the implementation plan for Vietnam’s Just Energy Transition Partnership, a $15bn G7-funded project to help wean Vietnam off fossil fuels.

No official information on Nhien’s accusation has been made public.

Hong has been recognised internationally for her work: she joined the Obama Foundation Scholars program in New York in 2018 and was listed by Forbes among the 50 most influential Vietnamese women in 2019.

When she was detained in May, the UN’s human rights body was among many international groups to voice concern, warning of the “chilling effect” of tax cases against civil society groups.

Among the four green activists jailed last year was Nguy Thi Khanh, a globally recognised climate and energy campaigner who won the Goldman Environmental Prize in 2018. She spent nearly a year in jail before she was released last month.