An elderly businessman has been sentenced to spend seven and a half years in exile in Russia for filming and selling pornography involving dozens of underage children, DailyMail.com has learned.

David Lang, 65, a 'respected' business consultant and English teacher from New York, ran his sinister illegal film studio for nine years in Chelyabinsk, a town at the foot of the Urals, before he was taken into custody.

The court saw graphic films and pictures showing him sexually abusing his victims, as Lang also subjected one underage teenage girl to repeated sexual abuse.

Police identified more than 50 children - including many under 14 - who were victims of his abuse, a court found. He was sentenced to serve his time at a penal colony.

David Lang, 65, a 'respected' business consultant and English teacher from New York, was sentenced to seven and a half years in a penal colony in Russia. He ran his sinister illegal film studio for nine years in Chelyabinsk, a town at the foot of the Urals, before he was taken into custody

The court saw graphic films and photos of him sexually abusing his victims, as Lang also subjected one underage teenage girl to repeated sexual abuse

Lang was friendly with US diplomats in Russia, pictured with Ambassador Alexander Vershbow and Thomas Niblock, the consul-general in Ekaterinburg. Pictured: Lang with Niblock

He was found guilty of 'sexual intercourse and other acts of a sexual nature with a person who has not reached the age of 16', but no penalty was imposed due to the statute of limitations relating to the crime.

Lang worked with a Russian accomplice named Ekaterina Yasina, a single mother who acted as his interpreter, who found the girls who Lang used in his films.

She also did their hair and make up for photo shoots.

Yasina - who hid her face in the hood of her jacket - was given a three year suspended sentence because she is the mother of an underage child.

Lang was convicted in a closed-door trial and then appealed the verdict, but his plea was this week rejected.

He sent child porn films on CD-discs to the U.S. by express courier and the money he earned went into his American bank account, according to officials.

Lang worked with Ekaterina Yasina (pictured), a single mother who acted as his interpreter, who found the girls who Lang used in his films. She also did their hair and make up for photo shoots. Yasina - who hid her face in the hood of her jacket - was given a three year suspended sentence because she is the mother of an underage child

Lang, who had previous addresses in Forest Hills, Flushing and Brooklyn, has been living and working in Russia since the early 2000s, authorities said. He also held a driving license from California

The American started streaming porn via the Internet in 2014.

He was dramatically detained when armed police were lowered on ropes from his apartment building's rooftop to break into his flat by smashing the windows.

Lang was seen as a 'respected' English and business tutor and known to senior US diplomats in Russia.

Before his arrest, Land was pictured with then-US ambassador to Russia, Alexander Vershbow, who served in Moscow from 2001 to 2005.

He was also photographed with Thomas Niblock, the American consul-general in Ekaterinburg.

He sent child porn films on CD-discs to the U.S. by express courier and the money he earned went into his American bank account, according to officials. Pictured: Lang's computers

He was dramatically detained when armed police were lowered on ropes from his apartment building's rooftop to break into his flat by smashing the windows (pictured)

It is believed Lang took part in US programs to develop democracy in Russia.

Lang, who had previous addresses in Forest Hills, Flushing and Brooklyn, has been living and working in Russia since the early 2000s, authorities said.

He also held a driving license from California.

Lang posted child pornography online and his illegal activities went on from June 2006 to November 2015 when he was arrested, according to state investigators.