Insurance giant American International Group Inc. may get wrapped up in a defamation case involving billionaire Elon Musk, who has told lawyers representing the British cave diver suing him that he’s financially illiquid, according to a legal filing.

An attorney for Vernon Unsworth, who sued for defamation last year after Musk attacked him on Twitter, pressed the Tesla Inc. CEO’s lawyer last month for information on all insurance policies applicable to claims made in the suit. An exhibit filed Monday shows the two attorneys sparring over information regarding Musk’s ties with AIG.

“Given Musk’s sworn testimony that he is financially illiquid, Mr. Unsworth is entitled to know whether AIG has accepted coverage of the claims, denied coverage of the claims, or has reserved its rights to contest coverage of the claims,” Unsworth’s attorney wrote on Sept. 20. Musk’s lawyer wrote back the same day that AIG had reserved rights, without elaborating.

AIG declined to comment on the filing.

“Mr. Musk’s insurance carrier was notified of the money-grab,” Alex Spiro, the Musk’s lawyer, said in an emailed statement. “It is a non-event.”

Unsworth’s attorney, Lin Wood, declined to comment beyond the filing.

While Musk, 48, has a $23.6 billion personal fortune that ranks him No. 38 on the Bloomberg Billionaires Index, he’s relatively cash-poor. Much of his wealth is from his stake in rocket company Space Exploration Technologies Corp., and he has said he has no plans to sell any shares. He owns about $8.8 billion of Tesla stock.

A trial of the defamation case is scheduled to begin Dec. 3 in Los Angeles.

The case is Unsworth v. Musk, 18-cv-08048, U.S. District Court, Central District of California (Los Angeles).

–With assistance from Katherine Chiglinsky.