Police probing Madeleine McCann’s abduction have received photos taken by British tourists in Praia da Luz showing “interesting things”.
Prime suspect Christian Brueckner, 43, is back in jail following hospital treatment for two broken ribs which, he alleges, came from a scuffle with guards.
Chief prosecutor Hans Christian Wolters said: “We got leads from England, including ones from tourists on holiday in Portugal during this time.
“We got some photos where there might be some interesting things on them.
“There are quite good leads we are following up.”
But he said the information would take time to pursue and when the UK leaves the European Union this could take even longer as “many things can’t just be clarified at short notice”.
There were reports in Germany of developments in the case of three-year-old Madeleine who vanished on holiday in the Portuguese resort of Praia da Luz in May 2007.
But police in Hanover categorically denied any searches carried out were linked to her disappearance.
Mr Wolters said the formal hurdles in the McCann case post-Brexit will get bigger.
He said: “In the EU everything was unified, and there was a uniform legal assistance between the European countries.”
But when the UK leaves he said Germany would have to “make a formal request, which means that we then write a very formal letter and then query everything individually”.
Phone records put Brueckner near the scene on the night Madeleine went missing.
He is serving a jail term for drug offences in Kiel, Germany.
He was sentenced to another seven years for raping a pensioner in Praia da Luz in 2005 but is appealing against his conviction.