The thief had a partner who would buy a bus ticket and place the suitcase in a bus from Girona airport to Barcelona in northeastern Spain, police said in a statement late Tuesday.

"Once the trip began, he would get out of the suitcase, search for valuable objects and hide them in a smaller bag he carried with him," regional Catalan police said.

The thief would then get back into the suitcase, to be reclaimed by his partner at the end of the 90-minute trip.

Alerted by the repeated thefts, police inspected a suspicious bag on the bus on June 3 and opened it up. "They saw there was a man doubled up almost like a contortionist," the statement said.

The man had a mobile phone, a small bag and a sharp object to open zips and locks, police said. Officers boarded the bus and detained the man who had left the suitcase in the luggage compartment.