Francisco Nicolas Gomez Iglesias, a fresh-faced 20-year-old dubbed "Little Nicholas", had dinner with friends on Thursday and left without paying 500 euros ($570), a police spokesman said.
"The young man then went to a nightclub were he was detained for fraud. He was questioned and released," the spokesman said.
Spanish media said he dined with about 20 friends at an upscale restaurant in the centre of Madrid and the group left after paying just 1,300 euros of their bill of 1,800 euros.
Staff then called police but the owner of the restaurant decided not to press charges after Gomez's friends promised to pay the outstanding amount owed, according to the press reports.
"Little Nicholas" first made headlines in Spain in October 2014 when he was arrested for allegedly passing himself off as a government adviser and asking a top businessman for a 25,000-euro commission to act as a go-between in a real estate deal.
Gomez was bailed while police investigated the case. He has appeared in photos in the press alongside a string of top political figures.
Among the personalities "Little Nicholas" has managed to rub shoulders with are Spain's conservative former prime minister Jose Maria Aznar and Rodrigo Rato, the former head of the International Monetary Fund.
But his crowning exploit was to sneak uninvited into a reception that following the swearing in ceremony of King Felipe VI in June, when he was photographed in suit and tie, bowing and shaking the monarch's hand.
Spain's secret service agency, the National Intelligence centre, has filed a lawsuit against Iglesias for saying he worked for the body in several radio and television interviews.
His story has captured the imagination of the Spanish public.
Internet users have taken to superimposing images of "Little Nicolas" on to photos of famous scenes in film or history to imply ever more ludicrous scenarios, from sitting next to Jesus at the Last Supper to encountering Darth Vader.