The company is developing 'Royal Beach City-The Goa' near Ganeshpura village on Vataman-Dholka highway, 45 kms from Ahmedabad.
Oberoi had signed a MoU with the Gujarat government for this project a few years ago when Narendra Modi was the Chief Minister, and announced an investment of Rs 200 crore.
The actor today met Gujarat Chief Minister Anandiben Patel and Tourism Minister Saurabh Patel.
He said the company decided to double the investment after the Gujarat government announced its new tourism policy recently.
"We appreciate the new policy. It boosted our confidence to invest more... we are now planning to double our investment and take it to Rs 400 crore," Oberoi told reporters.
"As a businessman, I want to admit that no other state is having such a favourable tourism policy. I wish other states adopt it. It will take some years to complete the project, but our club house will be operational within one year," said Oberoi after meeting Saurabh Patel.
"The entire project, spread over 100 acres, will offer 25 recreational activities. There will be an artificial beach to give a feeling of Goa's seashore complete with artificial waves, and also a golf course," he said.
Patel welcomed Oberoi's decision. "He told us they are very impressed with the new policy and intend to double the investment. There are many other entrepreneurs who are showing keen interest to start their projects here to take advantage of lucrative provisions under new policy," he said.
The new Tourism Policy for 2015-20, rolled out last month, gives the sector industry status and offers many concessions and incentives.