Zhengzhou pollution
Buildings in Zhengzhou where Guthrie McLean was arrested NICOLAS ASFOURI/AFP/Getty Images

An American student who was arrested in China after an altercation with a taxi driver has been freed, Montana senator Steve Daines has said.

Guthrie McLean's mother, Jennifer McLean, had alleged that Chinese police demanded the equivalent of thousands of dollars from the family and threatened Guthrie with years in prison if the sum was not paid, the Associated Press reported.

In an email to Daines' office, Jennifer McLean reportedly wrote: "Prayer's answered. Guthrie's home".

Guthrie McLean, 25, was arrested a week after allegedly throwing a taxi driver to the ground when the driver was arguing with his mother, who is deaf, over a fare.

Lawmakers from Montana had argued that McLean's detention on charges of intentional injury were unjustified.

"I am thrilled to report that we just received an email from Guthrie McLean's mother that 'prayers answered, Guthrie is home,'" Daines said in a statement.

"After days of working the phones with top Chinese and American officials to secure Guthrie's freedom from a Chinese detention facility, he has been safely reunited with his mother."

Montana Senator Jon Tester said: "As a parent, there is nothing more nerve-wracking than being concerned about your child's safety. I am overjoyed that Guthrie is safe and sound and will be reunited with his mother.

"This really is a testament to what can be accomplished when we turn up the heat and hold government accountable."

"As a parent, there is nothing more nerve-wracking than being concerned about your child's safety. I am overjoyed that Guthrie is safe and sound and will be reunited with his mother. This really is a testament to what can be accomplished when we turn up the heat and hold government accountable."