A granite monument of the Ten Commandments that has sparked controversy since its installation on the Oklahoma Capitol grounds was being removed late Monday and will be transported to a private conservative think tank for storage.

A contractor the state hired began removing the monument shortly after 10:30 p.m. The works comes after the Oklahoma Supreme Court’s decision in June that the display violates a state constitutional prohibition on the use of public property to support “any sect, church, denomination or system of religion.”

The state is paying the contractor about $4,700 to remove the monument and take it to the Oklahoma Council of Public Affairs; offices a few blocks away, Office of Management and Enterprise Services spokesman John Estus said. The Oklahoma Highway Patrol had increased security around the monument earlier Monday, and barriers were erected to keep visitors from getting close to it. Estus said the decision to remove the monument under the cover of darkness was made to avoid disturbing workers at the Capitol and to keep protesters from demonstrating while heavy equipment was being used to detach the two-ton monument from its base.

“We wanted it to be done as quickly and efficiently as possible, and doing it at night gave us the best opportunity to do that,” Estus said. “The Highway Patrol was also very concerned that having it in the middle of the day could lead to having demonstrations of some kind.”

Originally authorized by the Republican-controlled Legislature in 2009, the privately funded monument has been a lightning rod for controversy since it was erected in 2012, prompting a lawsuit from Bruce Prescott, a Baptist minister from Norman who complained it violated the state constitution.