"Our charge is to protect public access to land along the shoreline, and one of the ways we do that is to understand what the historic use of an area might be as a way to establish the public's right to access an area," said Charles Lester, executive director of the commission.
The commission opened its website www.coastal.ca.gov for the public to list how and when people used the beach in years and decades past.
If the agency decides to pursue fines against Khosla, it has a new weapon.
Last month Gov. Jerry Brown signed a budget bill into law which gave the commission the power to fine property owners up to $11,500 a day for illegally blocking public beaches or violating coastal environmental laws, similar to the tool already used by other state environmental agencies that regulate air and water pollution. Before now, the commission had to take property owners to court, which could take years.
"We will let the courts decide what the law says in the context of the issues surrounding Martin's Beach," said Dori Yob, an attorney for Khosla.
Environmentalists cheered Thursday's news.
"We really applaud their efforts and look forward to working with them," said Mark Massara, an attorney with the Surfrider Foundation, which is in the midst of a lawsuit against Khosla, claiming that his decision to padlock a gate to a private road to the beach required a permit from the Coastal Commission.
"It's long past due for the state of California to speak up on behalf of public access to Martin's Beach," he said. "This is the state providing an opportunity for people to speak up about their use of the beach over many years. This would further enhance the commission's prosecution of his violations of law."
Khosla, co-founder of Sun Microsystems, purchased the 56-acre coastal property along Highway 1 in 2008 for $32.5 million. His staff closed a gate and put up no trespassing signs along a private road that the previous owners, the Deeney Family, had used to allow the public to access the beach for a fee for many years.
Khosla, 59, has said that he is entitled under his constitutional rights to private property to close the route, that he didn't need a permit from the Coastal Commission to do it and that the public didn't previously have free access to the remote beach, like at to other beaches along the coast.
In an interview last week, Khosla said he doesn't intend to back down, blasting news coverage of the controversy and accusing his opponents of "blackmailing" him into giving up his property rights.
"If the story was right and people thought I was doing something wrong, I'd live with that it wouldn't bother me," Khosla said. "But there are massive lies and misrepresentation on the issues here. Surfrider and the Coastal Commission are attempting to coerce and blackmail me."
The Commission sent a "Notice of Violation" to Khosla in 2011, and has been privately negotiating with him to reopen public access.
"We would much prefer to resolve this violation by mutual agreement," said Lester.
Paul Rogers covers resources and environmental issues. Contact him at 408-920-5045. Follow him at Twitter.com/PaulRogersSJMN