A Russian scientist accused of being a Chinese spy died less than 2 days after his high-profile arrest

• A Russian scientist accused of state treason died days after being taken into custody.
• Dmitry Kolker, was terminally ill from cancer at the time of his arrest, his family said.

A terminally-ill Russian physicist has died just days after being arrested and accused of state treason, said his family.

Dmitry Kolker, a scientist at the Novosibirsk State University, was hauled up last week by agents from the Russian Federal Security Services — known as the FSB — on suspicion of being an operative for the Chinese, Reuters reported, citing Russian state news agency TASS.

According to the BBC, Kolker worked with quantum physics and lasers and occasionally gave lectures to Chinese students while accompanied by an FSB agent.

Reuters reported on Sunday that Kolker — who was terminally ill from pancreatic cancer at the time of his arrest — had died.

Alina Mironova, a woman identified by several media outlets as Kolker's daughter, confirmed his death at 2.40 a.m. on Saturday on her Vkontakte social media page.

Mironova also detailed her father's arrest on June 30, when he was taken in FSB agents despite being in poor health. In a separate post on Saturday, she said she hoped her posts would allow people "know the truth" about her father and not allow his "good name to be tarnished."

According to Reuters Kolker was shuttled to Moscow after his arrest, before being brought to the Lefortovo prison. He died in a hospital close to the prison, per the outlet.

Kolker's son, Maxim, told Russian news outlet The Insider that "some sort of coercion" had been exerted on his father by the agents who took him from the hospital.

"They called him in for questioning, they wanted him to testify against chief researcher Bagaev and the director of the Institute of Laser Physics. He said he would not tell untruths and things he didn't know about," he said, per the outlet.

"The last contact I had with my father was at 6.15 p.m. on the flight to Moscow. He said he was saying goodbye," said Maxim Kolker, per The Insider. He added that his father required intravenous feeding at the time of his arrest.

"He was a scientist, he loved his country, he was working in his country despite many invitations from leading universities and labs to go work abroad. He wanted to work in Russia, he wanted to teach students there," Kolker's cousin, Anton Dianov, told Reuters.

Dianov also called the charges against him "absolutely ridiculous" and "extremely cruel and unusual."

"To me, somebody who was producing such beautiful things could not have done what they accuse him of. And that's forever how I'm going to remember him," Dianov said.