Ex-US President Donald Trump is suing his former lawyer for $500m (£400m), alleging breach of contract.
He says Michael Cohen breached his duty as attorney to act in his client's best interests.
The lawsuit comes amid escalating attacks from Trump allies on Cohen, who is a key witness in a New York investigation into the ex-president.
A Manhattan prosecutor last week charged Mr Trump with fraud in relation to hush money payments to a porn star.