MOSCOW — Last year, he tried to bring former NFL quarterback Tim Tebow to Moscow to play for his American football team. Now American businessman Mike Zaltsman sits in a crowded jail cell, accused of breaking a window.

The Boston entrepreneur is involved in a dispute over an office he rented from a Russian billionaire that culminated with his arrest in April.

The case underscores the unpredictable business environment in Russia, where thousands have ended up in jail because of disputes or raids by rivals. Even seemingly petty crimes are used to imprison people for months or years.

In the property dispute, Zaltsman alleges he was persecuted by Andrei Gorodilov, a tycoon who counts London-based billionaire Roman Abramovich as a business partner and friend.

Although the property dispute is murky, Zaltsman’s treatment is excessive by any standard, advocates say.

“The fact that he was jailed for a broken window – this is cruel and sadly typical of Russia,” said Yana Yakovleva, founder of the advocacy group Business Solidarity.

Zaltsman, who has dual Russian and U.S. citizenship, was accused of hooliganism – a broad charge that has been used against the feminist punk band Pussy Riot and Greenpeace environmental activists. If convicted, he could be imprisoned for up to seven years.

He denies he was delinquent on his rent, and says he has had no contact with U.S. Embassy officials. A State Department official disputed this, saying U.S. diplomats have been in contact with Zaltsman and were monitoring the case.

Tensions have escalated this year between Moscow and Washington over Russia’s annexation of Crimea and its perceived role in the bloody conflict in eastern Ukraine, along with a rise in anti-American sentiment.

But there has been no suggestion that this played a role in the Zaltsman case.

Zaltsman grew up in Russia before moving to Boston in 1996 at age 19 with his parents, one of many Jews to leave after the collapse of the Soviet Union. He became a U.S. citizen five years later and built a fortune in shipping and media ventures that he values at $10 million.

He returned to Russia in 2005, setting up his Black Storm football team, which last year won the Russian championship. He failed in a bid to sign Tebow, the former Denver Broncos quarterback, to his roster.

For seven months, the 37-year-old Zaltsman has been in Detention Facility No. 5. He says he shares a cell with up to 15 others, with no trial in sight. Each prisoner has just 21 square feet of floor space, barely enough to lie down. “Almost no sky and sun can be seen here,” he said. “I’m forgetting how it looks.”