Clive Cussler, shown in February 2007 in court, sued the movie producers of Sahara, saying it flopped because he didn't have script control. He's now on the hook for the company's legal fees. ((Nick Ut/Associated Press))

Author Clive Cussler's legal losses over his novel Sahara and its movie adaptation continue as a judge ruled Monday the author must pay $13.9 million US in legal fees to a production company.

Los Angeles Superior Court Judge John P. Shook agreed with lawyers for Crusader Entertainment, who argued that Cussler owed them legal fees based on an original contract between the company and Cussler.

That contract called for an award of legal fees if either side breached it.

Shook said the fees requested were "reasonable and necessary."

Cussler sued the company in 2004, alleging Crusader had reneged on an agreement, which gave him approval rights over the film's screenplay.

The 2005 adventure film starring Matthew McConaughey and Penelope Cruz was a box office bomb.

Crusader hit back, accusing Cussler of inflating the number of novels sold in order to trick the company into producing the film.

The case took 14 weeks and jury members were told that Cussler claimed he sold 100 million copies of the book, rather than the actual 40 million.

In May 2007, a judge ruled in favour of the production company and Cussler was ordered to pay $5 million US.

Cussler also filed a counter-claim for $8.5 million US, saying he still had a deal for the company to option another book of his and they owed him that money. He lost that fight in January.

Cussler's lawyer Bert Fields said he would appeal Monday's ruling.