Phan Imex was supposed to build 10 buildings to house evicted residents and built eight instead.
A US official said this week that Obama could participate in an Asean summit to be hosted in Cambodia in November.
Asean countries are facing a multitude of issues which includes a dispute over the South China Sea.
Meanwhile, the US is making diplomatic efforts to improve its relationship in Cambodia.
Thirty-eight people remain in unlawful detention after they were seized by authorities as they protested outside City Hall this week.
The demonstrators were seized Wednesday, where they had demanded the courts release eight representatives arrested earlier this month.
Around 300 families lost their homes in the Jan. 3 forced eviction of Borei Keila.
An estimated 20,000 Cambodians are trafficked throughout the region each year.
The site, at Phnom Bath mountain, is 50 kilometers outside the capital and lacks clean water, electricity, and health care facilities.
Moek Dara is accused of abusing his post to gather hundreds of thousands of dollars in bribes and organizing drug trafficking.
Thailand forcibly returned more than 100,000 Cambodians last year.
In a meeting this week both foreign ministers said they would speed up negotiations over joint development in offshore blocs.